I am Alkata Kanwar and I am really happy today because I am shooting the most awaited video of this year. I know that a lot of you were really waiting for this video in which I am going to share my views about the NTNET exam that happened in the month of December 2018. So finally, here is the video in which I am going to talk about the major changes and I am going to comment and give my analysis of the paper one of the NTNET exam. But before I talk about the major changes and I highlight the main important things that you must make a note of, I would like to wish you all a very, very, very happy New Year. On the eve of New Year, that is on 31st December, I shared a post on all the social media pages in which I was talking to my students about how should they react to the last NTNET exam that happened. And that post was dedicated to all those who gave the December NTNET exam and they were upset about the fact that it did not go as expected. And I was amazed to see that the post went viral. Like people were so happy to read that post. They felt motivated. They felt as if they are ready to face the battle. So thank you so much for the love and wish you a very happy New Year. You know, I always believe in the idea that nothing is going to change if the year changes externally, but nothing inside you changes internally. So this year, make a promise to yourself that every day you are going to do something to make yourself a better person. So before I talk about the paper, I would like to tell all of you that if you are not aware, I have already posted the official question paper and answer key on my website, the link of both paper one and paper two is given in the description box below. So if you haven't seen the last paper, then it's time for you to go and check out. Apart from that, now it's time to look at the main changes which were there in this paper in paper one particularly. So the first major change that I found in the paper was the new interface. For the first time, the paper was conducted online. Earlier, the paper was conducted as a pen paper test. So OMR sheet was given to you. But for the first time, the paper was online because of which a few students were facing problems like a few students commented that, you know, they marked all the answers but they got to click on the button save and mark for review because of which not even a single answer of theirs was accepted by the computer. So even after giving the entire paper and, you know, giving a super paper, their answers were not evaluated. At the same time, there were a few students with whom I had a phone conversation and they said that, you know, the computer interface was not so user friendly. They had to shift the screen, scroll left and right in order to see the entire question which was quite disturbing for them. But apart from these minor mistakes, I think that the online interface was really good. Number one, it definitely had saved a lot of time of these students because, you know, you don't need to go back and fill the bubbles. At the same time, the chances of committing errors in filling the bubbles were decreased significantly because now you just need to click on the computer and you need to proceed to the next question. So if I sum up, I would like to say that the online interface was good but it could have been better and I'm hoping that NDA would definitely improve their system in the coming. The next interesting fact I would like to share is that when I was going through the 22nd December paper one, I found that the paper was extremely simple. If I talk about data interpretation which actually gives a lot of stress to the students, the table was super easy to understand and super easy to calculate because the digits were like 15, 20, 25. So very normal digits were there rather than having any decimal digits. Apart from that, reading comprehension was fabulous. It was very easy. If you talk about the sections of communication, computers, you will find that, you know, the questions were very direct. For example, they'll ask you that what is the other name of the non-verbal communication? Okay. Then there were questions like which of these are not audio formats? So we all know these basic things. So overall, I found that the paper was easy. I'm specifically talking about the paper which came on 22nd December shift one. Okay. Because my students, those who are appearing for industry literature, they gave that paper. So I have actually sat down and analyzed that paper. And my interpretation is that paper one was comparatively easier. The next important thing that I noticed was that there was a shift in the paper pattern. If you look at the paper one of 2016 or 2017, you must have found that they were asking five questions from each of the 10 units. So in total 50 questions were asked. This time, there was a shift in the paper pattern. There were some sections from which they asked seven, eight questions. From the other sections, they were hardly asking one or two questions. General awareness, which actually scares a lot of students from that section this time, very less questions were asked. So if you are having intellect level of Alia Bhatt, then I'm pretty sure that you were saved. Apart from that, you could have seen the same thing in different units. For example, teaching aptitude, research aptitude. These were the sections from which more number of questions were asked. So you need to understand the thing that now leaving any of the units would not help because you don't know from which unit more number of questions would come and from which unit less number of questions would come. So you need to cover the entire syllabus for paper one. The fourth important thing that you must have noticed in this year's paper one was that this time they asked questions from new topics. So some new topics were introduced. For example, if you look at reasoning, earlier they were asking questions like relationship or they were asking us about solving any equation or asking about statement and premises, when diagram. But this time they asked us distance time question. Then they also introduced clock questions, ratio questions. So these were few areas which were untouched by the students. So now it's on you that looking at the new pattern, you need to even expose yourself to the new areas which you were not touching earlier. Apart from that if you will see a significant change, you will find that this time's paper one was very similar to the other competitive exams like BAM, PO or SSC. So the paper pattern was different and they are trying to make it very similar to the other competitive exams. So now it's on you that you need to start learning something more and you just cannot define the syllabus. The syllabus is becoming vast and the radius of the syllabus is stretching day by day. So now that I've highlighted the main important changes, you must have this question in your mind that how should we plan for the next exam? What should be the strategy according to the new pattern? So the first important thing that I would like to mention here is that please don't panic. I've seen this tendency in a lot of students that whenever there's a change in any conventional paper pattern, they'll stress out. They'll start feeling as if, okay, something has gone wrong. Now understand some changes are for your good. This time's paper was easier. Okay, so if you devote about an hour every day for the next few months, paper one will be a very, very scorn in paper for you. And if you look at the questions, if you calmly sit down and analyze them, you'll find that most of them are common sense based questions. So with practice and if you are observant around the world, then definitely paper one will be your kind of thing. The second important thing that you must remember when it comes to the strategy is that become computer friendly. Guys, it's high time that you should go paperless. Even today I've seen students who prefer pen paper more than computers. We've got so many good apps on which you can make your notes, so many good websites on which you can practice mock tests. So it's high time that you should start using computers more because once you get computer friendly, you will automatically feel that this computer based test is far more effective than the OMR pen paper test. Another important thing that you must make note of is that say no to guidebooks. Now I might not make any sense to you at this time when I say this because you might question that if not from guidebooks then from where should we study? Understand guys, if you look at the paper, you'll find that nothing was from the guidebooks that are available in the market. There are a lot of guidebooks which are there in the market but the information given in the guidebooks that is irrelevant for this paper. Now if you see that the paper pattern is very similar to bank, PO, SSC, you can make use of YouTube videos and then from YouTube itself you can prepare for paper one. When I was preparing for paper one, I actually did not buy any guidebook. I was solely relying on internet and on YouTube for most of my information. So it's very important that you break that conventional study pattern and start using internet as a source of information. You'll find that there are a lot of YouTube channels which are giving you free information for paper one. And so many videos are there that you can easily understand any concept. You don't need to buy any paid material for paper one. That is what I'm saying from my experience. And you can also see that the same thing applies in the case of other papers as well. Now another important thing that you must make note of is that previous year papers will help you a lot to score high in UGC net paper one. The reason being is that when you start solving previous year papers, you'll find that there are very similar questions which are repeated every year. Okay and if you have mastery over those questions then in less time you can score really high. It's not about hard work, it's about smart work. So you must go through the previous year papers, start solving them wherever you find that you're making a mistake. You can go to YouTube, to other websites and then you can study that concept from there. And that is how you'll make your own notes. And these notes will give you higher marks than any other guidebooks can give you. So these are few important tips that you must remember if you are aiming for the next NTA net exam. So with that note I end my discussion on the recent NTA UGC net paper one. I hope that this video helped to clear a lot of your doubts. Also I'm hoping that this video gave you clarity and gave you broader understanding on how to prepare for paper one. I'll be putting a lot more videos on paper one on this channel so if you have not yet subscribed to the channel then it's time to do that. Also please follow me on the other social media platforms because I keep posting important updates about the UGC net on those channels and those platforms. If you have any questions, any queries, any suggestions you can put that in the comment section below and I'll be very happy to address that in the next video lecture. Thank you so much. Happy learning. Keep loving your Trature. Stay tuned to article5r.com


This paper discusses how mobile internet devices can be used to form the general professional component of bachelors in electromechanics competencies in modeling of technical objects. Various methods of representing models were discussed, such as using SyLab, SageCell, Google Sheets, and XCos on cloud in the formation of the general professional component of bachelors in electromechanics competencies in modeling of technical objects. The paper also discussed the advantages of using these software applications for mobile internet devices, including cloud-based spreadsheets as modeling tools, a visual modeling system as a means of structural modeling of technical objects, and a mobile computer mathematical system used at all stages of modeling. Finally, the paper discussed the importance of using mobile communication tools for organizing joint modeling activities. This article was authored by Yaviniai Omodlo, Sirhi Osamerikov, Ruslan Pishajda, and others.


Hi everybody, welcome back to our podcast the Kamasutra helpline. I am Seema Anand. I'm the Kamasutra expert and with me Of course is Dr. Anritha Madan Bihal, psychosexual therapist as well as a relationship counsellor. And with that today You have a really fascinating question for us. Don't you? I do I do This is from a 16 year old boy from India. He writes that I'm writing this email from my father's email I'm writing this email to get an answer to a question regarding my sexuality and fetish Since childhood, I have a fetish about men's pot bellies since class 7 I have a recurrent bad habit of masturbating to videos of men bloating their bellies and gaining weight However, I have never been aroused by any of my male friends in school or any good-looking male film stars I have crushes on girls, but I'm not aroused by them. This creates a dilemma in me about my sexuality I've asked my parents many times about this, but they have no answer So I decided to ask qualified experts about my problem I saw your video about fetishes in Seema Anand's YouTube channel and I would love a response to my question Under what a fascinating question I mean, there are so many things that are coming into my head that I want to talk to you about but before we actually Start there are three things that I'd like to say one is that yes, you and I have done a lot of work on fetishes And in recent weeks, I've been talking about some of the more unusual fetishes I find that because they're unusual because they're so out to the box It doesn't go down very well with people People are very judgmental about anything that is outside of their understanding They don't get it and they react really badly to it. So I think people who go through This kind of kink shaming for what they like and a fetish is simply how you feel pleasure You've said many times a fetish has got nothing to do with your sexuality So I think a lot of people don't want to be open about their fetishes because they feel they're going to be kink shamed And we're going to talk a little bit more about that. I want to just say that You know, it's I don't think I've ever come across anybody else who's ever had a thing about a man's pot belly And it just goes to show we've always said that there is somebody for everybody out there in the world And so yeah, there's obviously a room for excitement for a man's pot belly Which is fascinating even for me because I haven't come across this but to come to the question Let me just break it down very quickly So that we know what we're answering. So this young man says that he's turned on by the sight of Men's pot bellies. He masturbates to the idea of the pot belly of a male He doesn't find himself being turned on or being sexually aroused by any guys Whether good-looking or other guys who are in his class that he's not turned on by any guys Plus he's not turned on by any girls in his class Either and now he's wondering about his sexuality Do you want to sort of run us through this to start with because I think that it's fascinating that He's not actually attracted to either side. He just says that the idea of the pot belly is what turns him on Yeah, and and I and I really I thought this was such an interesting question from a 16 year old and I just want to say get go I'm really amazed that his parents are involved like he used his father's email address to write to us And I really as in I'm really proud of these parents because they're obviously allowing a dialogue with him and not shaming him About this dialogue. So, you know, just want to start with a shout-out to the parents and this young man But what I will say is that I think what happens is that we are preconditioned In society from a very young age that this is how we're going to figure out our sexuality, you know Who do we sexually like? How does it work? And but more problematic is that we are preconditioned to say just because say we like one thing like oh, I I liked kissing a boy that means you're gay So now you're in the you know You're in the box that says you're gay or I actually had an experimental night with a girl or I touched a girl You know I was in the class and I brushed against a girl and I touched her breasts and it felt really exciting Am I a lesbian? So and what I love about today's generation and the today's time is that there seems to be room to say Let it roll out, you know, let it play out in some ways Different experiences will teach us different things about our sexuality Sexuality is something that is fluid. It's changing and it's okay that it is fluid and it's changing So my first thing to this young boy would be, you know, it's very easy to say Fetish of male potbellies. So that means I'm gay and that is not it's not actually an equals to in any way Fetish is something that you feel aroused by And it's interesting that you get aroused by men's potbellies But you have figured there is this is one thing that arouses you and obviously we can break it down into what might have happened to arouse you with it But that's not what we're here discussing So just to distinguish between is it's wonderful that you have figured out what you know arouses you and what gives you pleasure What you are figuring out and I'm sure you will get the answer sometime Is to understand what your sexuality is. Do you like men? Do you like women? Do you like both? Do you like neither? So though at that question, I think is yet to be answered and I would just You know just suggest and advise to be open for whatever comes through rather than, you know, put yourself in a box I also want to add over here that you know, even if there is something particularly that turns you on It doesn't mean like you said that it's the only thing that's going to turn you on But also it doesn't mean that that's the thing that's going to take that pleasure through to the end So it might be your turn on point It could be that what you really want is to be with a female partner But that your first bit of arousal will come from this and as you get older You explore your mind your sexuality you explore other things and as you widen your horizons You'll find other things that turn you on as well. Do you think that's a possibility? and you know, I think that's such an amazing thing because What I would say to that is I think, you know media always feeds us A sexualized or something to be aroused by is a woman's body, right? So I would say so many women and men Get sexually aroused by looking at a woman's naked body because that's what we've been fed as prompts to get aroused You know, so of course we can go into the political debate about it But I think that's very true But does it mean that just because we See a woman's naked body and feel aroused by it or you know, a woman's body and feel aroused by it that be a lesbian We could be we could be on the continuum somewhere But that's absolutely right that There are there are things that you know, I think it's like our body remembers or it just touches something in us And suddenly that's sexual light bulb just switches on and that's what you're talking about like there are images Experience emotions touch and it just switches on the thing. But just because we have you know, it switched on Doesn't mean it will stay switched on and actually, you know, continue forever So I think we do need to work on the next steps as well But yeah fetishes are a good way to switch on something I think also you're right that your sexuality can be quite fluid depending on your experiences I think your basic understanding of Which way you swing And like you said most of us are somewhere on that spectrum on that continuum We could go in either direction I think I mean, I've always thought that your intrinsic idea of your sexuality Is always quite firm. But do you believe that depending on certain circumstances? You can actually go from one side to the other like you could Be different in your sexuality Absolutely as in so I've shared the story Before one of my closest friends when I met her was queer She introduced herself and she said she was queer and she spoke about a lesbian ex-partner And I said oh so in my head, you know, my Indian Just new head and limited perspectives. I put her in the box of being a lesbian She subsequently kept talking about the flatmate she had and how good looking he was and how attractive she was to him and I kept, you know feeling so confused in that moment because I kept thinking But she said she had the girlfriend Now she's being attracted to this man like what's going on But you know, she said she was queer like this is really confusing and from her I learned The fluidity of sexuality, you know It doesn't That you can be attracted to both people It doesn't mean that her identity became heterosexual just because she was interested in a man She was still queer because she at any point could have chosen and said oh actually today I met this woman and I'm madly in love with her and she might have been in a long-term relationship with the man So it's something that shifts and moves And people are more and more and this is what we talk about gender as well now that these are all socially constructed ideas and I know people like start criticizing this thing about people changing it However, you know the reality is if we don't put ourselves in the box and we keep allowing it most of us Most of us actually will feel this way most of us will be open to feeling like the young man said I have crushes on girls, right? So emotionally He does get attracted to girls not aroused right now by them But emotionally he has crushes and maybe tomorrow He will find a pot-bellied man in college and fall madly in love with him So I would just love the world to give room to everything that comes in some ways So if you were advising him or his question to you was that he is confused about his sexuality He doesn't know How to think of it. He doesn't know where to look To um to understand how he feels because I'm sure the way that he feels sets him aside from everybody else in his class like I said, I don't think that I've come across anybody else with this particular crush Lots of other unusual things, but not this particular one. So I'm sure it sets him apart from everybody else Like if you were advising him, what is the first thing you would say to him? I would say to him that he should stay completely open to experiences You know, I think what's happened in this case is that he figured out something that aroused him And I just I didn't like the word bad habit of masturbating.  He started questioning it And which is true. He might be as in that's not to say he might not be However, he did the right thing to say, okay, this speaks me. I'm started questioning You know, a lot of people are questioning. So he started his questioning phase And in response, he didn't get an answer. He didn't get an answer from other men or boys in his school from film stars But he also didn't get an answer from the girls So I think he is in this questioning phase and it's okay to be in this questioning phase I would just say be open to both, you know, experiences and ideas Maybe you've just not come across somebody you feel aroused or attracted by And maybe that person will come subsequently but don't In the questioning phase, what's important is to not close off You know, any doors like it's very easy to say this is going to be a tougher way to go Let me just choose to be heterosexual or this is the more popular way to go. So let me read this I think what's important is to be true to yourself and be authentic to yourself and just Allow things to open And and it's okay to be questioning and that's perfectly legit and okay to just be in the phase of questioning So I think what you're saying is that don't judge yourself for how you feel Um feelings come and feelings go and when you talk about saying that you're masturbating to something We've often said that how you masturbate what goes on through your head What brings you to pleasure And I think for most people masturbation also has to be linked to A specific person like sometimes you need to visualize a person In a particular situation For the masturbation to be successful, you know, for it to be good for it to be fulfilling So I think um What you're saying is don't judge yourself. Don't call it a bad habit. Don't say oh I'm masturbating to this and that's a bad habit that I've gotten into Yes, I think that once you fall into a habit of a particular thing It can be very difficult to change how you feel leisure afterwards If that's all you stay in so if I was going to give that bit of advice, I'd say Enjoy your masturbation to whatever image comes into your head But maybe also start exploring some other images so that You can understand for yourself that there is more to explore and there's more out there I think um, I find this a lot with Young girls who say that they've always masturbated by squeezing their legs together And I've said often that certainly in India where We don't have the chance to explore our sexuality in many different ways You stick to doing that because it's like a nice secret quiet way of masturbating It's just that secret way of nobody knows you're doing it. So it's like a safe way of doing it and You continue doing it for so long that that's the habit that you fall into And there are so many girls who now can't Ever orgasm with their legs open because they've got used to just doing it in that one way So although it's very pleasurable. It's fantastic. It's easy. It's quick. It's really really Exciting because it also is very pleasurable I think it's also good to explore other things just to keep your own options open And and I think what's important about that is that When we're young and we have just started masturbating or a recent The quickness of it or the easiness of it becomes really important because it feels like, okay, you know I can do this and this I know is a short short way of me getting aroused masturbating coming done, you know, it's not something I'm not sure how many young people really savor it and enjoy it and things like that So what I think you're suggesting is that yes, it's easy and yes, it's a great go-to But when you have the time and if you have the time Explore other go-tos because then that will just it's just expanding what gives you pleasure You know, it just increases what gives you pleasure Potbellies is one thing And what I was thinking when you kept saying about, you know, that's an interesting fetish I think it's very similar to some people being very attracted to big women And you know how we say all the time when people are talking about Bodies and body shaming and everything that there's so many times that we've heard men say that they actually prefer bigger women Than otherwise. So it is such a personal choice And there is always somebody for someone out there.  We want to play with your partner's poo. You want to play with that pee There are things that turn different people on there is There's no limit to the human imagination and what turns you on and that doesn't necessarily make you weird or Unsafe to be around as a matter of fact, if you understand what turns you on in your head And that's what you're doing to pleasure yourself. I think that That's the first step to being a really stable human being just understanding What gives you pleasure and understanding how to go to it I think um, one of the things that I would like to add over here is that When we talk about our pleasure when we talk about masturbating or we talk about how to Bring ourselves to arousal You know with girls particularly we are now starting to teach women or girls That masturbation should be done really slowly. So we're when we talk about this because you know for the longest time Women's pleasure has been so taboo So women are only now coming into this area of being able to pleasure themselves And we go out of our way to say to them take your time Give yourself the space make sure that it's a nice comfortable safe clean space Um, make sure that you have the chance to explore your body. We're really going out of our way to say Give yourself the time and the space and do it slowly. And like you said you use the word savor it with boys I feel that there aren't enough male sexual health experts and there isn't enough advice being given to boys to say Savor it do it slowly most guys do it Literally very very quickly one because they don't want to get caught and Two because they feel that the quicker they get it over with the quicker It's kind of done and they can move on with life So they're not looking at it as a thing of pleasure. They're looking at it as something of necessity Yeah, and you know, we also say the symbolism of where you do it It's a lot of time young boys tend to do it in bathrooms. They do it, you know quickly It's what's romantic in doing it in the pot. Like, you know, there's nothing romantic about that Or pleasure, you know, so it might be pleasurable But as in that is and so to be fair like They're limited choices as well and we have to appreciate that that they're limited spaces sometimes that young people That, you know, can go in masturbate. So if that's the best option that is the best option However, if you do get the chance and opportunity and you can do it You know slowly thinking imagining things rather than using porn and You know, really understanding your body and your pleasure Then it is something thinking about it. Just thinking about it Like you're imagining what arouses you what comes up what emotions there It is definitely way beneficial for your relationships When you actually start having sex with your partner Then the quickness of it, you know, watching porn coming quickly finishing it off quickly and everything That tends to impact us and there's a lot of research now on how that tends to impact sexual relationships and later life With partners. Yeah, so I think What I would like to say in closing is that Thank you so much for writing this question into us. Thank you for being brave enough And I think like you said a big thank you to the parents for allowing this child to be brave enough to ask Rather than being shame being shut down being told that you can't talk about this. You're too young Actually allowing him to explore this so that it gives him a better chance for his own emotional stability as he goes further We hope that we at least put your mind at rest a little bit by saying that There is nothing unusual in what you're doing. If you haven't figured out your sexuality just now It is absolutely okay.  People have lots of different fetishes.  Enjoy it Do start to explore a couple of different ways of bringing yourself to pleasure in your mind Just actually have a little exploration because I mean how much fun is that under the being given permission to say Go explore in your head.  Yeah, and and really just adding to that. I think What would be key in this process is to be open and not to judge yourself like I think I'll stay away from words like bad habit You know, there seem to be a you know, I hope there is no judgment on being attracted to potbelly so What I would just add to that is just that stay away from judgment Be open and honest the more open and honest you can be about your experiences and what you like and dislike The more authentic you will be with your sexuality And that I think really helps in the long term in your life So good luck with figuring it out and I hope this video was helpful and we were able To answer some of your questions that you were struggling with. Yeah, some of the doubts. Hopefully yes If you found this video helpful useful as always, please do like comments subscribe If you have any questions to ask I am on info dot sima dot anand at gmail.com And if you are seeking a consultation, you have unvita on unvita dot madhan behel at gmail.com But as always, of course the details will be in the caption below do write into us and as always Till we meet again. Take care of yourselves. We will see you here soon


Everton! Everton! Everton! Everton! I'm glad you've played, they haven't been fighting for the club or each other after what happened last week but, he's sent out theorus, is the time everything seems to be against us as he said whether it be the decisions with VAR, whether it be the injuries to key players. The players have got a knuckle down now on fight for each other and fight for the fans and try and get those 3 points tomorrow, and I think as far as he's been saying, you know, everton is a good goal. mae gwybod, mae'n gilydd i'r pwyntigol yn cael eu falch, ond nesaf werthio'n b Chef yn coifio'r brifwyl ac mae'n cael ei gweithio gan oedr i dda i'r dweud hynny i gael i cofio'r fan. Na yw'r cas na dwi'n rhaid i fewni llawer, ond ond mae'n gweithio'n gweld ei chael… maen nhw a ddi i ddim yn cael eu fwy awrthau yn rhaid i ddim yn cael eu fwy awrthau. One of those players who will hope to be fighting the Shentoson and he's actually said he keeps fighting, he's been fighting and training for his position and has had faith that he'll get a chance and he believes that what happened last week coming off the bench was a testament to his hard way. Not only that but speaking to the manager and listening to the manager and understanding exactly what the manager wants him to do. He says he speaks to Marcus Silver quite regularly after training about what he wants from the striker and he's hoping for a chance and it's going to be interesting to see whether he gets that chance, whether he's going to get an opportunity now to get a start forever after the goal last week. We'll have to wait and see on that, we'll have to wait and see but I think for Shentoson it all comes down to the way Everton play more than anything. Everton play with an isolated striker then there's very little point to having him on the pitch from the start, he's the kind of play that you can see come off the bench. In fact when we need a goal I think he is a perfect play to come on, if he's scrambling round last week like we needed a goal he is a perfect play to come on but we haven't really seen that out of him either recently. So we'll have to wait and see, we'll have to see what the manager does tomorrow. He's still got striking options and he's not even using those striking options, obviously we all know it's the midfield that way. We are absolutely decimated in and again Fabian Delth seems highly unlikely that he'll play tomorrow but we'll just have to wait and see. He has trained a little bit this week but he's up to that level, we'll find out tomorrow. Tom Davis, one of the midfielders, well who will be involved tomorrow, he's been called up to the England under 21s, he had a really really good couple of games for them before he got back in the side so hopefully it will continue with a good game tomorrow for him and hopefully it will continue with some good performances for the under 21s. Finally Andy Gray has had to say on the managerial situation that some fans have muted as a possible long term successor and he said he's the man Everton should go for in the summer. He said the fact that Man City have brought Van Broncoost to the club suggests that he is the person they want to replace Pep Guardiol with long term. Micka Latetson would just be the perfect person to come with Evan, obviously being a player with Evan and obviously being a really good student of the game under Arsene Venga and now being an assistant coach to Pep Guardiola. He's got that ground and obviously he hasn't been a manager yet and that's what a lot of people will talk about. Recently we've had Franclan Pard has gone into Chelsea after a year at Derby, we've got Stephen Gerrard up at Rangers, almost preparing for life to become the Liverpool manager, it seems after Jürgen Kloppen. I suppose to worry for someone like Micka Latetson is if you wanted him to go somewhere first to be the manager and he did a really good job then other clubs might start looking at him so that's what Andy Gray thinks anyway. What are your thoughts? Let me know in the comments. Make sure to check out the match preview if you haven't already. This start on 11 show is available now and a host more shows if you're on Patreon as well. If you're not on Patreon the link is in the description. Thanks for watching Toffy TV, I'll see you later.


Hello and welcome to today's lecture on micro strip antennas. This figure shows a rectangular micro strip antenna. So, we have a ground plane over here then a substrate and on top of the substrate we have a rectangular patch. If you really see this looks very similar to the circuits which we have discussed earlier like power dividers couplers filters and other things. Now in case of microwave circuits what we do we try to send signal from point A to B on the PCB itself. In that particular case we do not want any radiation to take place. Whereas, in case of micro strip antenna we want this patch to radiate in the free space. So, how do we achieve this? There are two things which we need to do. So, that a micro strip circuit behaves a better micro strip antenna and these two things are we should try to choose epsilon r value as small as possible and we should choose the thickness of the substrate as high as possible. That does not mean you can take very thick substrate there is a limitation that H by lambda 0 should always be less than 0.06. Now, as you can see it is a very very simple geometry. So, it has lots of advantages it has lightweight, low profile, planar configuration and which can be made conformal to let us say the host body which could be even a missile, helicopter, plane, satellite and so on. Since it uses a PCB technology. So, fabrication cost is very slow and also mass production can be done very easily. Both linear and circular polarizations are possible we will show you some of these cases later on. Also feed lines as well as matching network can be easily integrated with antenna structure itself. I am going to show you an example of micro strip antenna array where feed lines as well as matching network both are integrated on the same substrate. However, micro strip antennas have few disadvantages. One of the main disadvantages narrow bandwidth typical bandwidth of a micro strip antenna is of the order of 1 to 5 percent. However, I am going to show you the techniques how to increase the bandwidth of micro strip antenna. It has typically low power handling capacity after all it is fabricated on a PCB. So, it cannot handle very high power, but again I am going to show you one example which can handle very high power. There are practical limitations on the gain. So, one can obtain gain of around 30 dbi or so. For larger gain it is better to use parabolic dish antenna which I am going to cover after two lectures. Now, size of the micro strip antenna is large at lower frequency. You can think about if we are designing antenna let us say at 100 megahertz what is going to be the wavelength 3 meter. And if we design a lambda by 2 antenna that is going to be a very large antenna. However, I am going to show you some configurations where we can reduce the size of the micro strip antenna. So, because of so many advantages micro strip antenna finds several applications. So, these were used in pages of course, nowadays there are no pages, but it has been used in mobile phones micro strip antennas find application in Doppler and other radars satellite communication missile guidance systems feed element even in complex antennas and biomedical radiator. By the way this is not the complete list of applications there are many many other applications of micro strip antenna. So, I had shown you the configuration only of a rectangular micro strip antenna. However, there are so many different shapes which have been reported in the literature. So, these are square circular triangular semi circular annular rings square ring. In fact, there are shapes like pentagon hexagon and so on also, but today in my lecture I am going to focus mainly on rectangular micro strip antenna. So, let us see how we can find the resonance frequency of a micro strip antenna.  You can see that I have shown dotted line over here which actually represents effective length as l e effective width as w e. So, where is this effective length coming into picture. So, just recall now I showed you there is a micro strip patch which is on top of the ground plate. So, there will be fringing fields from the edges. So, these fringing fields account for additional capacitance. The additional capacitance can be compensated by simply extending the length outwards. So, here I am just going to show you that l e is nothing, but equal to l plus 2 times delta l, where delta l is the extension in one direction delta l is extension in the other direction.  Now for the fundamental TM 1 0 mode, what is TM 1 0 mode? Well, one actually implies that there is a one half wavelength variation along the length ok. I am going to show you these things in more detail in the next slide, but 0 implies no variation along the width. So, now recall dipole antenna what is the effective length of the dipole antenna it should be lambda by 2. So, here also effective length of the rectangular patch l e should be equal to lambda by 2, but since it is printed on a substrate lambda is nothing, but equal to lambda 0 divided by square root epsilon e. So, why there is a epsilon e and a not epsilon r? The reason for that is most of the field will be confined within the substrate material, but part of the field will be going in the air. So, to account for the field in the air we use effective dielectric constant. So, over here so, if we now substitute the value of lambda 0 as c divided by f 0, where c is velocity of light. So, we can write the expression for f 0 just note it is c divided by f. So, f 0 will become c divided by 2 times l e square root of epsilon e. So, l e is given by l plus 2 delta l and the value of delta l can be approximately calculated as h divided by square root epsilon e. I will also show you later on what is the expression for epsilon e, but right now let us see the characterization for T m 1 0 mode. So, for T m 1 0 mode as I mentioned there is a one half wavelength variation along the length. Now, you can see that this is the voltage distribution, this is the current distribution. The reason for that it this is an open end at open end current will be equal to 0 it will go to maxima and come back to 0 why because the total length is equal to lambda by 2. And since it is open circuit here voltage is maxima here it goes to 0 and then it goes to the negative maxima and field is uniform for T m 1 0 mode field is uniform along the width. So, you can see that this voltage will remain constant and voltage will remain constant along the width. So, now let us see how the fringing fields will vary. So, from here you can see that the fringing fields are going outward to the ground. Since we are feeding at this particular point over here we are assuming this voltage is positive. So, for positive voltage field will be going from here to the ground and as we move along the length you can see that the field intensity will keep reducing as you can see the amplitude will keep on reducing and then the direction changes and you can see that now the field will be like this here. Now you can see here most of the field is confined within this dielectric medium, but part of the field is actually in the air and that is why we use the term epsilon effective for characterizing rectangular microstrip antenna. Now these field distributions can be resolved into two components vertical and horizontal component. You can see that this vertical component is going upward this vertical component is going downward. So, these two field cancel out in the broadside direction. However, if you look at this particular thing the direction of this is in the right hand direction you can see it is going in this direction. If you look at the direction of this one here it is also going in this particular direction. So, the analysis of rectangular microstrip antenna can also be done by assuming that there is a one slot antenna over here there is another slot antenna over here and the amplitude of these two fields are equal the reason is this is plus v this is minus v and we can apply array theory to find out the radiation pattern. So, just think about one slot antenna another slot antenna and we can actually find out the total pattern by multiplying the slot pattern with the array factor. Rectangular microstrip antenna can also be modeled as a transmission line the fundamental mode of rectangular microstrip antenna can be modeled as transmission line reason for that is there is a no field variation along the width. So, this length is approximately lambda by 2. So, we have a radiation resistance in parallel with capacitance which is nothing, but fringing field capacitance this is the radiation resistance corresponding to this particular slot here and then there is another one on this particular side . So, now let us see how we can design rectangular microstrip antenna. So, generally speaking design problem will be that frequency is given to us and desired bandwidth will be given to us and then we have to design the length and width of the rectangular patch, but before we do that we have to choose appropriate substrate parameters. Later on I am going to show you how to choose these appropriate substrate parameter, but let us just assume that we have chosen substrate parameters as epsilon r and h. Then first step is to calculate the width. So, width can be calculated using this particular expression over here. Now in this particular case I just want to mention you can take smaller or larger w then the w obtained by using this particular expression depending upon what is the requirement. So, just want to mention if you take a larger w then what will happen? Bandwidth will be more as well as gain will be more. So, bandwidth is proportional to w as well as gain is proportional to w. Why gain increases? Because total aperture has increased. Why bandwidth is increasing? The reason for that is that as w increases fringing fields will increase. If fringing fields increase that means there will be a more radiation and hence q will be small and if q is small bandwidth will be large. Epsilon effective can be calculated using this particular empirical formula. There are many different formulas are there, but I have found this formula to be best suited for designing rectangular microstrip antenna. Epsilon e can be calculated for chosen value of substrate parameters epsilon r and h and whatever the w value you have chosen substitute over here. And then we can find out the value of l e for given frequency value. And then after we have calculated l e find the value of l I have given already expression for delta l. Then comes the next point what should be the feed point location. So, I am just giving you a simple rule of thumb that choose feed point x between l by 6 to l by 4. Generally we choose l by 6 for narrow bandwidth antenna and l by 4 for broadband antenna. So, let us take a design example. So, I am taking a practical design example of Wi-Fi application. Now Wi-Fi works from the frequency range of 2.4 to 2.483 gigahertz. So, we choose some substrate parameters epsilon r is 2.32 h is equal to 0.16 centimeter and tan delta is 0.001. Now you might wonder why we have chosen these parameters. In fact, I will tell you beforehand only these are not the optimum parameters for this particular application, but sometimes you know we learn better if we make mistakes. Then I will take some substrate parameters see what we get. Then I will tell you how to improve the design. So, first step is to calculate w I had given the expression in the previous slide. So, c is equal to 3 into 10 to the power 10 this is in centimeter ok not in meter. If in a meter it will be 3 into 10 to the power 8. So, 3 into 10 to the power 10 that is in centimeter, then down below is 2 into f 0. So, center frequency of this is 2.4415 into 10 to the power 9 and epsilon r plus 1 by 2 is equal to 1.66 it comes out to be 4.77 centimeter. So, we have chosen w equal to 4.7 centimeter. For this value of w we can now find the value of epsilon e which comes out to be 2.23. You can see this value is slightly smaller than the value of epsilon r. So, now we can find the value of L e. So, by substituting various values it comes out to be 4.11 centimeter. After that we can calculate the length L equal to L e minus 2 delta L what is delta L h divided by square root epsilon e. So, that comes out to be 3.9 centimeter. So, now we are going to take these values and do the simulation. Now, we take these design values of L equal to 3.9 centimeter w equal to 4.7 centimeter and as I mentioned take x between L by 6 to L by 4. So, L is 3.9 centimeter. So, we chose x equal to 0.7 centimeter and these are the substrate parameters. So, simulation has been done using I 3D software. So, you can see here this is the input impedance plot and this is the reflection coefficient plot. Z in is equal to 54 ohm at f equal to 2.414 giga as you can see this frequency is slightly different than what we had done the design for. Now, let us see what is the bandwidth. Bandwidth for S 11 less than minus 10 dB is from 2.395 to 2.435 gigahertz which is equal to 40 megahertz. In fact, the desired bandwidth is much more than 40 megahertz. So, let us see what needs to be done now. So, first start with the analysis. So, we had designed this antenna for f 0 equal to 2.4415 whereas, simulated value comes out to be 2.414 gigahertz that means, percentage error is about 1.1 percent. In fact, we have given you very very simple design equation and if you are getting error of only of the order of 1 percent in fact, it is a very very good starting point. Now, to improve the design of the antenna all you need to do it is use this particular thing f 1 l 1 equal to f 2 l 2. So, for example, in this particular case we had taken l as 3.9. So, l 1 is 3.9 centimeter. What we have obtained here that is 2.414. So, put 2.414 here and then what is the desired frequency 2.4415. Calculate the value of l 2 use this value to do the simulation you will get nearly perfect result. Now, comes the next part bandwidth is small. So, what do we do? Bandwidth is small solution is increase the height. So, just to tell you bandwidth is proportional to the substrate thickness. So, if you double the substrate thickness bandwidth will also increase by almost 2 times and if you increase edge remember you have to reduce the value of l slightly why because if you increase edge fringing fields will increase that means, delta l will increase. So, l has to be reduced slightly. So, I am going to now show you how to properly choose substrate parameter. So, here is the plot substrate thickness is plotted along the x axis this axis shows efficiency of the antenna and this axis shows bandwidth of the antenna. So, plot is for 2 different values of epsilon r this is for epsilon r 2.2 this is for epsilon r equal to 10. So, you can see that as substrate thickness increases for this particular case let us say bandwidth keeps on increasing and bandwidth keeps on increasing for this case also, but you can see that bandwidth is much more for epsilon r equal to 2.2 as compared to bandwidth for epsilon r equal to 10. However, let us see what is happening to the efficiency as we keep on increasing the substrate thickness you can see that the efficiency is decreasing and for epsilon r equal to 10 efficiency is relatively poor. So, in general I want to tell you please do not use very high value of epsilon r for designing rectangular microstrip antenna or any microstrip antenna. Generally, choose lower value of epsilon r. So, that you can get better bandwidth as well as better efficiency. I just want to also mention if you take epsilon r equal to 1 you can just think about extrapolating this result. So, for epsilon r equal to 1 this curve will be going something like this. So, that means, you can get much better bandwidth also efficiency curve instead of going like this efficiency curve will be almost like this here. So, by choosing lower value of epsilon r you can get better bandwidth as well as better efficiency. You can see that typically bandwidth is of the order of 5 to 10 percent even though you can see here bandwidth is 15 percent, but corresponding to this particular case you can see efficiency will be relatively poor. So, that is the reason majority of the time people say bandwidth of the microstrip antenna is relatively small. So, that you can get a better efficiency, but later on I am going to show you lot of broadband antenna configurations. So, this table shows effect of the dielectric constant. So, here are multiple cases of epsilon r starting from 9.8 to 4.3, 2.551. Now, when we reduce the value of epsilon r length will increase correspondingly, width will also increase correspondingly. We have designed all of these parameters for f 0 approximately equal to 3 gigahertz and you can see that bandwidth increases as epsilon r decreases. So, epsilon r decreases, size increases. So, bandwidth increases as well as gain increases. Why gain is increasing? Because total aperture has increased both L and W have increased because of the low value of the epsilon r. So, let me show you the radiation pattern of the rectangular microstrip antenna for T m 1 0 mode. So, this is the E plane pattern, this is the H plane pattern. Don't get confused it shows here E theta in phi equal to 0 degree plane. So, E theta phi equal to 0 degree plane is this one here. So, this is E plane and perpendicular to that will be E phi in phi equal to 90 degree plane. So, that corresponds to H plane radiation pattern. Here there are two plots are there one plot is for epsilon r 2.32, another plot is for epsilon r 9.8. So, one can see that as epsilon r is reduced from 9.8 to 2.32. So, what has happened? Half power bandwidth has reduced. So, why is that? Because as we reduce the value of epsilon r size increases, size increases mean gain increases and gain increases mean half power bandwidth will decrease. So, same thing you can note for H plane pattern also, this is for epsilon r 9.8, this is for epsilon r 2.32. Now, we will talk about various broadband techniques. So, first technique which I am going to talk about is gap coupled rectangular microstrip antenna configuration. So, here only one patch is fed other patches are parasitically coupled. In this particular case these patches are coupled along the radiating edges of the rectangular microstrip antenna. This is the configuration where parasitic patches are placed along the non-radiating edges of the fed patch. Here four patches are placed along the four edges of the rectangular microstrip antenna. You can see that only one patch has been fed and all other patches are parasitic patches. So, let us see the result. So, I have actually shown the result for four edges gap coupled rectangular microstrip antenna. I have shown all the parameters over here epsilon r H l equal to w equal to 30 mm or you can say 3 centimeter. Feed point is almost at the edge which is 14 mm from the center. So, these are the dimensions for the parasitic patches along radiating edges. So, both the parasitic patches along the radiating edges are taken identical equal to 27.5 mm. The gap between the patches is taken as 2.5 mm. However, along the non-radiating edges length of the parasitic patches again taken equal, but equal to 25.5 mm. In this particular case gap is much smaller. The reason for that is along the radiating edges field is uniform. However, along the non-radiating edges field is varying sinusoidally. Since field is varying sinusoidally coupling will be relatively weak. Hence, we have to take smaller gap to increase the coupling. You can see two loops in the Smith chart over here. This is lowest frequency, this is the highest frequency. As frequency increases this particular patch becomes resonant. So, this loop corresponds to length l 1 and then you can see another loop here. This loop corresponds to the length l 2 which is happening at the higher frequency. You can see that both the loops are within VSWR equal to 2 circle and that you can see from VSWR plot versus frequency and you can see that the bandwidth for this particular configuration is almost 18 percent. So, you can see that it is not 1 percent, 2 percent or 5 percent. It is a very large bandwidth and in terms of megahertz it is 569 megahertz bandwidth. Now this is the another configuration where patches are electromagnetically coupled. So, there is a one patch at the bottom layer. There is another patch which is put on the top of the bottom patch over here. Here we have used thick metallic plate and these are suspended in the air by using a central shorting post over here. You can see this is the feed point for this particular antenna configuration. So, let us see what are the dimension. So, l 1 is 15.2 centimeter we have taken square microstrip antenna. So, l 1 is equal to w 1 which is 15.2 centimeter that is the dimension of this one here. L 2 is the top patch dimension is 12.8 centimeter, delta 1 is the gap for the bottom patch which is 1.1 centimeter, delta 2 is the gap between the top patch and the bottom patch which is 1.3 centimeter. And in this particular case l g is equal to 24 centimeter l g corresponds to length of the ground plane. So, you can see this is the radiation pattern of this particular antenna. You can see that radiation is mainly in the broad side direction and there is a very little radiation in the back side. So, we can define front to back ratio as this value subtract this value in terms of d b. So, that is approximately 15 d b. This is the gain plot versus frequency. You can see that over this particular bandwidth gain is almost flat which is of the order of 9 d b i. And measured bandwidth for v s w are less than equal to 2 is from 870 to to up to 1000 megahertz. It covers the g s m 900 band from 890 to 960 megahertz. Now, let us see how we can realize a compact microstrip antenna. As I mentioned earlier at lower frequency size of the antenna becomes large. So, here let us see the field distribution of T m 1 0 mode again. So, field varied from minus to 0 to plus and along this width field is uniform. So, you can actually see that along this particular thing field is 0. And if the voltage is equal to 0 that can be replaced by a short circuit.  So, that means, we have reduced the size by almost 50 percent. In fact, instead of shorting this entire width if we just put single short over here size will reduce even further. In that particular case what will happen? If there is a single short then this length will become lambda by 4. One can also realize compact antenna by cutting slots within the rectangular patch. So, just think about this was the original rectangular patch. We have cut one slot over here we have cut another slot over here it looks like the shape of a edge. Now, in case of rectangular microstrip antenna length was from this point to this point which was equal to L. But however, for edge shape m s a effective length will be now equal to average of the lengths from this point to this point and going around up to this here then another path over here then another path over here. So, you have to take average of these path that means, total path length will be definitely more than the length L and hence frequency will reduce. So, we can realize a compact antenna simply by putting shorted over here. So, if we do short circuit over here. So, now we can say that this particular length will be approximately equal to lambda by 4. So, size is reduced further. In fact, I have just shown one slot over here one can use multiple slots. So, that effective length is increased thereby reducing the frequency of operation. Now, we can also obtain circular polarization using square microstrip antenna. So, what we need to do it is this is a square microstrip antenna. So, we feed along x axis let us say with one angle 0 we feed along y axis by one angle 90 degree for left hand circular polarization. Now, I just want to mention again for this particular feed this is actually null ok that means, 0 field. So, hence any feed over here will not affect the performance of this particular feed here. Similarly, for this particular feed this is orthogonal point. So, that will correspond to the null or short circuit. So, hence this will not affect this particular feed. So, both the feeds will be isolated from each other. So, let us see the radiation pattern of this particular antenna. So, I have shown here not normal E theta or E 5 pattern, but I have shown here EL and ER. EL is left hand circularly polarized component, ER is right hand circularly polarized component. So, you can see that it is a good left hand circularly polarized radiation pattern and the orthogonal component here is relatively very very small. Now, let us take an example of array to increase the gain of the antenna. So, 8 by 8 corporate fed microstrip antenna array is shown in this particular slide over here. So, you can see that the entire feed network is also integrated along with the patches. So, let me start with this 2 by 2 array first. So, we will start with the 2 by 2 array first. So, you can see that there is a feed at the edge at the edge impedance will be relatively high. So, hence we have to use a quarter wave transformer at this particular point quarter wave transformer we put it over here and then another quarter wave transformer has been placed over here to transform this impedance to about 100 ohm. Now, this is identical to this particular portion. So, 100 in parallel with 100 will be 50 ohm. So, that means, if you just use this 2 by 2 array feed over here you will have a 2 by 2 matched array ok and that will of course, have a more gain compared to a single patch. Now, this 2 by 2 array is extended to 4 by 4 array you can see this is repeated over here. So, another 2 by 2 another 2 by 2 another 2 by 2 and now these are connected together. So, again as before what we do we transfer this impedance using quarter wave transformer another quarter wave transformer to transfer this impedance to 100 ohm 100 in parallel with 100 will become 50. So, just this particular thing will become 4 by 4 array this particular concept is extended to 8 by 8 array. So, let us see the result of this particular array. So, we have again simulated using I3D software you can see that this is VSWR plot versus frequency. So, you can see bandwidth for VSWR less than 1.5 is from 8.55 to more than 9 gigahertz which is about 5 percent bandwidth. Let us see the radiation pattern at 8.75 gigahertz which is approximately the center frequency of this particular antenna. So, you can see that this is the main beam and there are multiple side lobes are there. Please recall array theory when we talked about linear array and planar array I did mention to you there will be side lobe levels. So, here there are 2 plots are there they look kind of identical, but there is a one plot for E plane and another plot is for H plane. So, E plane half power beam width is 9.9 degree which is almost same as that of H plane half power beam width which is 9.4 degree. Side lobe levels you can see that they are below 12.5 dB other side lobes are below this particular value here and the gain of this particular antenna is 21.3 dB. So, just think about for a single patch we had a gain of 6 dB for a dipole antenna we had gain of only about 2 dB, but by using an 8 by 8 microstrip antenna array we can obtain a gain of about 21 dB. Of course, this concept can be extended to 16 by 16 array or even 32 by 32 array to realize much larger gain. So, just to quickly summarize today we talked about microstrip antenna which has several advantages that is why it finds lot of applications. There are certain disadvantages such as small bandwidth, but we talked about 2 different configurations to increase the bandwidth. It has the disadvantage of higher size at lower frequency, but we talked about compact antenna to reduce the overall size of the antenna. It has the disadvantage of low power handling capacity, but we showed you 2 metallic plates which were suspended in the air and supported by metallic post at the center that can handle kilowatts of power. It has the disadvantage of small gain, but we use 8 by 8 corporate fed array to realize gain of 21 dB i. Of course, gain can be increased by using larger number of elements. So, thank you very much.


TAPS Transportation Services API and how that relates to retiring the BSD socket API. Please give him a great round of applause and I'm welcoming him to the stage. Hi, so my name is Phil or Philip Tiesel and I'm today here to talk about TAPS the Transport Services API. All the work I'm presenting today is work in progress. So it has become a fairly large group of people working on that and it's really awesome how much traction it got but it's still work in progress. So we have no ROC yet, we are just talking about internet rafts and preliminary stuff we're doing for the API but on the other hand we have already have a few implementations and it's really nice seeing how much traction this gets. But before talking about why I want we want to replace the BSD socket API or want to retire it let's see what's wrong with that. So looking at the BSD socket API we have to go back in its history and you see the BSD socket API originates from 4.2 BSD from 1983 I was two years old when this was released and therefore it has become quite old. At this time it was they were really very strong in the idea of everything is a file and as we didn't have virtual file systems yet in this time they decided okay if we want to do networking just make it a file handle and have instead of an open call the socket call and everything works like a file and it was implemented as an extension for inter-process communication so instead of doing inter- process communication on a single machine we're now doing it over the new shiny internet which was quite small at this place and time and work yeah as an experiment and they decided to say we have two kinds of APIs for inter-process communication a message-based you can easily also create in the new mix domain socket and a stream-based and for this they implemented the user datagram protocol UDP which is unreliable and the transport control protocol TCP which is reliable stream and as it was the first really nice real API that ought to be usable and it doesn't require to fiddling with network drivers or putting a similar code in to come that but enabled everyone who was able to write a file to also do network in the process communication it became the template of most modern networking APIs if you look at the BST socket API and look at the Windows socket API or other socket API on embedded platforms they look quite the same they're all modeled after the original BST socket API so let's see what we need to open a socket this is the classical example from Stevens at all Unix network programming this is still the reference on how to do this so you first create an integer variable to put the socket file descriptor as file descriptors are integers then you reserve a struct for the the name resolution configure it a little bit and call get other info with all this stuff and to get the return parameters now you have a linked list of stuff that allows you to to connect and as the results of the name resolution if it fails to get an error and then it gets worse you start a while iterating about this list and trying can I connect the socket if it works we're fine if it doesn't work try the next one tree try to connect if it works we're fine if it doesn't work it blocks its timeouts and we go to the next drop and try to drive the next one afterwards we have a socket file descriptor we have a special free that allows us to free the whole list and we're done so simple question what's wrong with that and I'm not thinking about modern APIs but just on what's wrong if you accept that CS program that way what's still wrong with that and the question the answer is today's internet transport has changed we're not in 1983 anymore and therefore a few things changed first we have much more many more protocols out there than just TCP and UDP at the narrow waste of the internet we now have ipv4 and ipv6 and not ipv4 anymore at the transport layer we don't have we have sctp as a reliable message-based protocol we will become quick we will get quick pretty soon so it's rolled out at the moment primarily from Google but Akamai is on the way and a lot of other CDNs or contrast distribution networks are on the way to roll out this so we'll have a second transport protocol pretty soon that is made for replacing TCP at least if HTTP is on the on top of that and probably you want to use this transparently as the second change we have devices that have multiple paths today so if you had the mainframe in 1983 you were really lucky if you had a permanent connection to the internet and were not dining and up through 300 bout modem today you have a cell phone that has multiple network interfaces at least one cellular carrier and at least a Wi-Fi interface probably you can use multiple at the same time and you might want to really decide on a per socket basis which pass to use and finally you have multiple endpoints serving the same data if you're looking if you're talking to Google or any other CDN you just get the front-end cache and you have several to choose from and finally last but not least everything today should be encrypted at the oldest of the internet everyone was trusted we don't need to encrypt communication you can trust the other a few hundred guys on the internet you know them today we need encryption to save everything and these are all things that were not sought of when inventing the BSD circuit API so let's look how we can fix that we go to our textbook example again and have first to look at the name resolution we want to resolve names over multiple paths in parallel and to make things worse if you're talking to CDN nodes you cannot use the same IP addresses through all links because if you have a Wi-Fi from the camp and for example a T-Mobile LTE on the camp those will most probably deliver you different DNS results for CDN nodes and you might not be able to reach the other CDN nodes at all for using the wrong link so you have to resolve in parallel you have to keep the results separate and you have to use them in the right way the BSD circuit API doesn't provide this feature so if you want to do this in an application for example the web browser you have to implement your cold DNS yourself welcome second if we have results these DNS results contain information that will be later on useful for your secure connection setup if you want to do use features like SNI encryption that allows that prevents some observer on the past to see what hosting you're connecting to you have to get a key from DNS the current second API doesn't provide you this you will need and you you will have to implement DNS yourself so thing if you want to connect users usually like fast connections if you have to time out multiple times if you have to time out 90 seconds per connection attempt the user gets annoyed if you click on the website a link and it takes you three or five minutes to display something the users really really angry so what you what all browsers do today or what you have to do today if you want to be state-of-the-art you have to try multiple connections in parallel so you try IPv4 and IPv6 with a small head start for IPv6 wait which socket connects first and use that one so no loop anymore but a fancy loop around select who in this audience likes select or e-paul or paul as a programming concept oh we have quite a few so it really gets ugly to code this and with things like quick emerging we will have to do the same for the protocol so this is ugly then we need to set up a secure transport so for example SSL which is not part of the socket API but this is a separate library you're using and you're separately take care of that and finally you have to pass the transport protocol chosen so if you use TCP or quick or whatever you use back to the application because the socket may have slightly different semantics whatever you chose I sort about presenting a code example of that and we're looking for something so there's no textbook example there's nothing on stack overflow by the way the nicest and shortest example I found was in libcurl and it was about 1000 through 1200 lines of code okay so how the heck do we solve that the usual idea of people are asking that question say oh no way there's no way of replacing the beasties socket API don't just don't think about it would work several researchers tried that and failed and I only have one reason why I'm hoping that this approach might succeed so why I'm standing here last year bunch of people who got really annoyed about the beasties socket API because they broke their research code or were really ugly in the API design met at the tabs working group at the ITF and said oh we have to do something about this and the group who initially met was first a bunch of academics and then Apple joined and we're saying oh yes we built our new network API we want to standardize it here work together with you who all have worked on different aspects of this connection set up and of this automatic probing of different transport options let's work together and let's build something new and they really are now trying to release the socket API or the new network framework that's basically what we're currently standardizing at the ITF okay I talked about the ITF the ITF what the heck is the ITF and what the heck is the tabs working group first the ITF is a standards body that looks sounds pretty boring so a lot of people talking about standardization and how to interoperate with things not quite because the ITF is a pretty unusual standard bodies and also if you visit the meetings you will find out it's a pretty nerdy place I think these two quotes characterized the ITF pretty well so the first is from David Clarke and saying we reject Kings presidents and voting we believe in rough consensus and running code which is quite unusual for standards body because usually you the standardize something that someone else already had as a product or you're just standardizing something everyone's agrees on and nobody knows whether it will ever be implementable and the second one is be conservative in what you send and be liberal in what you accept so if I want to interoperate with others I should keep to the standard as much as possible but I should be able to tolerate failures from what the other send and also in the ways the ITF works you see this is quite different from other standards body so there's no voting shares for different companies but there's individuals in a room that try to find consensus and they usually decide whether to get to the consumption by humming so instead of saying are we have raised our hands to vote there's the question who is in favor of the the following proposal please hum now and you just get a feeling on how much the people humming in the room and if you're really in favor of it you can hum loudly and really for the full voice you say okay I can live with that but it's not so convincing you can hum silently and as it's a very deep voice you can't really get who is voting for what so it's in person it's in the room it's easily about viable and it's more less anonymous that's awesome so how's this ITF organized first it's divided into several areas so their applications in real-time or art area is mostly concerned about application protocols and on protocols that are doing real-time transport then there's the general area which is mostly concerned with stuff that touches everything else and doesn't fit in close to one area there's the internet area which is really about the IP protocol version 6 and perhaps looking at what the legacy IP needs for fixes there's of the operations and management which mostly talking about practice practice of how to manage networks the rooting area which is mostly about BGP and other rooting protocols the security area where things like TLS or IPsec gets standardized and the transport area and this is the area we're talking about today because we are talking about transports like TCP quick SCTP and this is also the area where tabs works so what's the tabs working group so the tabs working group is by its own charter concerned with transport services it started off as a group of people mostly thinking about ways on how to actually deploy SCTP and get a CTTP deployment but now with a few people joining and really talking about methods on how to choose sockets really on talking about methods how to use multiple access networks it got a lot more traction so the name is it is a little bit funny because who knows what tabs means for a usual American tabs is the melody you usually play when a soldier on a soldier's funeral which was something because many Americans laughed about the tabs working group but today as we try to retire the BSD socket API it might get a different meaning now the idea is to enable application developers to use other protocols than TCP and UDP without too much caring but so you don't want to rewrite your whole code if you want to use quick instead of TCP actually if it works you just would like that works just the same way you did it before we want to enable transport evolution and describe an API how to use transfers wait API ITF is the idea of just standardizing protocols why APIs so that's the reason why we really talk about an abstract API and there's a really really tight separation of concerns on what the ITF specifies in terms of protocols the ITF specifies abstract protocols so basically what primitives are there what are the basic interactions and APIs for concrete languages are usually made by their own standard bodies so for example if you look at the Unix see API is done by politics if you look at the Java API there's the Java community process for that and therefore what tabs is doing as a pro as a specification is just input for other standard bodies on how could we implement this in our language and it's trying to have fairly broad on abstract concepts there that are usually somehow able to be mapped in different language so the different the API's will look quite a little bit different and can neatly integrate within the language while you have still the same rough same interaction patterns and if you're going from for example objective C to Python you will see a similar API but that's fields objective C on your iOS device and fields Python that's got one Python that's the idea so how does this standardization stuff work in the ITF so we start with writing an internet draft an internet draft is for the academics from you something like a tech report or something like an archive or paper everyone can submit that everyone can write that it has to go through the ITF processing toolchain and provide this beautiful esky text but otherwise there are no real limitations for who and what you can do with an internet draft and then you I want to decide how do I want to publish it and if it gets published it gets an RFC number so how do we do this you can either say I'm working want to do this with in a working group then you carry your internet draft to the working group and said oh I have written this draft do we want to work together on that and adopt it as a working group item and if the working group says go away we're not interested or the working group says oh yes it's fine and the following five people also want to join you in working on that and this is what we did for tabs there's also this individual submission way where individuals can submit stuff but that's rarely used for real stuff because mostly you you're not writing RFCs alone then you get if you say think it's ready and you ask the related areas that are touching stuff your stuff please do a review look whether it works and whether you have insights that said it's a good or it's a bad idea and then you iterate over like till the other people are lucky so this is always because this is the blue file you iterate another round if someone is unlucky and if it doesn't find consensus so usually it gets about five to 25 rounds of rewriting a document before it might get an RFC after this effort after the reviewers from the other area said it's fine the working group said it's fine it's sent for the internet standard internet engineering group for review which is again a group of people who are ATF veterans and are elected by a very interesting process who say okay we have an overview about most stuff going on the itf we think it's a good idea and works or we say oh no you have overlooked something please fix it at the following western after the isg review comes in you send it to the RFC editor for publishing and they will tweak a little bit the wording have a little additional rounds with you on how to fix details and finally if all references are fixed if everything is fine it gets published as an RFC so if you're asking where tabs is at the moment tabs is at the moment here we have it accepted as a working group item and we are actively working on that and we'll soon get the first reviews from other areas so for ITF work it's quite early in the pipeline so what's the idea how does it work what are the idea principles so first it's an event-driven API so modern networking APIs or networking applications work asynchronously you always do select you always have to look about several sockets and several connections so you don't want to block anywhere and tabs has nothing that blocks so everything you do whether you initiate a connection you listen for incoming connection read or write if something's for you you get an event and whether the event is implemented as a callback or as a listener pattern object or some kind of work queue is totally up to the specific language implementation whatever fits into the language would should be used to implement these kind of events in addition if you're looking at these sockets it's really really complicated to get information like fire ICMP ICMP blocked or ICMP rejects it's really hard to get this information and tabs is going to make this information easily available as events to the application too the second basic idea and that's why it's in the tabs working group it should enable protocol evolution so we're focusing on what the application needs the application doesn't say i want a tcp socket but the application says i want a reliable in order stream socket and whether this is implemented as tcp or as quick or as scdp you don't care you get the service you're asking for and you can narrowly define with with properties what you really need and the system makes a smart choice for you second you want to be really flexible a connection establishment time so you want to use happy eyeballs for everything for protocol selection so for transport protocol selection for ip protocol selection maybe also for endpoint selection and if you have other preferences so for example you want to use them the cheapest possible link or something like that you just code this into the timeouts or the head start you give for the different kind of connections so if you give a 30 millisecond head start for a certain link these connections will establish first and will be used but if the link is broken or if something else is broken there just using the released preferred or the lesser preferred one that doesn't have the head start still you don't have to wait for some timeout you just get a connection and it feels fast and the third idea you want to be flexible after core connection establishment and you want to use features that modern transport protocols bring you like connection migration if you change your p address you don't want to reconnect you'll just carry on with your connection you want to be able to use multi paths if you have multiple links and you want to be able to use multi screaming to save connection time so your application shouldn't care about whether you need to open a second tcp connection if you want to parallelism or you open a second an additional quick scream if you have quick available and these all should be glossed over in tabs and as the third main concept we want to be able to do data transfer using messages all interactions in model networking applications are message based yes you have a tcp so that's a scream but you usually chop the screams into messages and work then on this messages and therefore we want to support framing and deframing for protocol message based protocols on stream transports because we are not going to change the transport steps we're just providing nicer interface to the existing one that's also the reason why a tab system can without any problem interact to any other system because we're not changing the protocols we're just changing the way you're accessing the protocols it allows to control a lot of stuff on them individual messages that are available in the protocols but not exposed by the socket API today like deadlines so for example in a city you just might not want to transmit a message when the receiver isn't hasn't any use for it anymore so you can associate a deadline with a message and it might be dropped from the send buffer after this deadline is over you might want to send certain messages unreliably because you don't care whether they arrive or don't care too much about that whether they arrive and you can all select this on a per message basis in a nice and suitable way and it also allows you to assign messages to underlying transport connections for multi streaming and for pool connections so if you're today open have a web browser that opens the connection to some cdn note or to some other website it opens a bunch of connections and distributes the request among them we can do this in the socket API and not you don't have to implement it yourself this should be done by a tap system how do we last this with two concepts that are central to do this the first one is framers framers are pieces of code that allows you to chop a stream transport into individual messages and the nice idea about this is you can just write the piece of code and then it integrates with the buffer management and back pressure management and you only get a message in your main application code once a complete message arrived or a chunk of the message if the measures are too large but you can really implement this in a nice and sensible way I think we should also be able to offload this for example to hardware so if you have something you are able to offer a lot of stuff into your hardware it might also look for the messages and only send the application into in software interrupt when a whole message arrived for it and finally this concept is mainly for chopping through stream protocols but we might tweak it a little bit and we might be able to implement just simple protocols also within this framing layer and finally to control all that stuff we need some mechanism and this means to configuring our transport properties so we have selection properties that influence pass and protocol selection we have connection properties that influence per connection behavior and with message properties that influence per measures behavior they just used like a dictionary and we have well-defined namespaces so we have default namespace for all stuff we are currently writing in this r of c and we have different namespaces for example for transport protocols specific stuff you just write tcp. and the property and you know this transfer property is only used if the connection is done using tcp if it's done using quick this is just ignored so how does this interaction work so if we have this on a textual basis we say i want a connection to example or using htps i need a reliable transport and please optimize for local latency in the tap system says oh yes nice here's a connection object now you now can send you and receive your messages on this and you don't have to care about anything else so it's not thousand one thousand two hundred lines of code but it's about 20 lines of code to could establish that connection so there is this nice sgr diagram from the architecture from the current draft that's saying basically the idea so you start off over with the pre-connection that's an object where you do all the connect configuration on you want to connect you specify a local endpoint a remote endpoint for example a hostname you specify selection properties and you specify defaults for the connection and message properties so you can for example say we have if even if i get a reliable protocol i want all my messages sent unreliable if possible you can already specify this in this stage then you go into the pre-connection on the pre-connection you can either call initiate and get a connection object once the connection is established or you can call listen on it and get a listener object that is listening for your connections once this initiation works you get an event so in this case a listener you you get a connect connector received event or in this case get an initially completed event and have a connection object on this you can send can easily call send with a message you receive messages events out of that and every close it goes to close connection fairly simple so how does this work look in abstract code so we have remote specifiers say i want a remote specifier with the hostname example com with the service https i want transport properties reliable in order stream this is a shorthand you can also specify a bunch of um properties on that you want reliable that you wanted in order and so on and you say i want the capacity profile low latency added to it that you optimize to latency then you configure your security parameters for the encryption and create a pre-connection object with all these parameters on the pre-connection you can say i want an htp framework that i just want to be want to get htp requests and responses as messages and don't want to care about anything else and then say pre-connection.initiate and get your connection object back the connection object then sends you an event saying oh i'm ready the connection is set up and then you can send your messages you generate a new message context configure it you want a lifetime of 200 milliseconds and tcp low delay if tcp is used if not you don't get it and then you have the connection i can send a program so Theresa who might be in the room here um and a few students of us and i have written this pyson azonc io tabs as one example implementation which is still on top of the bsd socket api to just see whether this how this fits into python and we see have this as an example application that does exactly the same as the two slides before of pseudocoded so we're not the only implementation at the moment there is much more complete as our python implementation uh the apple network framework which is available since ios 12 or 13 i guess so it's it was a better in ios 1200 will now come in ios 13 as default network communication framework and it's based on the ideas of tabs um and there are also some other projects which are need and socket intents which were pre-runners that gave input into the whole process but you can get some ideas on what a tab system could do from these frame from these implementations but basically if you want to use tabs today uh and your programming for ios you can just use network framework and you get most of the stuff i was talking about to you today just today by using it if you're interested in more stuff the documents are in the itf data tracker so you can see it if you're interested to collaborate if you have comments on that subscribe the tabs mailing list from the date itf data tracker and start discussing about that stuff we love input we love ideas uh we love if you see that there are problems because we really want to have the next generation socket api there and therefore we need input of whether use cases are sort of or whether this works nicely and if you want about the latest version the latest discussion there's also github repository where we also have github most detailed discussions as github issues so if you have a need or if you found a right spelling error in the documents just make a github issue and we'll take care of that so with this i'm finished with my talk and i'm happy to take questions hello hi okay sorry we just had a technical problem so thank you so much this was phil's and we have a bit time left for questions so please don't be shy and come to the microphones and ask away thank you you mentioned that the new api is supposed to include deadlines are these real absolute deadlines or just timeouts this is a good question so so we don't think that anyone will really implement a real time networking api because that's really really hard if someone is going into the area of deterministic networking where you can have real deadlines this might be as exposed as well as a transport property but the the timeouts i was seeing here are mostly advisory timeouts like gear stack we really don't need to retransmit this packet if it has lurked for about 300 milliseconds in the output buffer so it could be real deadlines at some point in time but at the moment we are just are for the actual implementations today we're thinking about per message timeouts thank you so much next question please so in your python example you awaited the send and then registered some sort of callback on receive after you awaited the send that looked a bit weird for me why do you need to await the send if you use callbacks anyway you don't need to wait at this point in time it was just in the example but you don't need to await it in this moment and maybe a related question so what kind of you said you wanted to be protocol independent and obviously there are many communication patterns that are interesting beyond just bi-directional byte streams so do you only plan to support bi-directional byte streams or something message-oriented broadcasting what so as i already told in the talk we are really looking about messages if it's possible oh okay so the default interaction should be messages and we have the framers to chop is byte stream into messages and that also should allow you to migrate from stream-oriented transport like tcp to a real message-oriented transport once this is available in your current deployment scenario if you're not looking about point to point we have some people who joined the tabs working group and joined our work that are really looking about source specific multicast and we definitely want full multi-cast support within this api but that's still at an early stage that's not in most of the implementations yet but it's coming so it's definitely on our agenda to include multicast in a usable and nice way and in a portable way thank you so much and i think we have a question left yes thanks for your talk do you foresee already how much of the implementations will be user mode and how many or which parts of implementation will be user mode and which parts will be kernel mode especially regarding the async parts which are usually done differently on different operating systems that's a very good question if you're looking at the implementation that are currently out there so there's our personal information is mostly of wrapper as the need implementation also is mostly a wrapper uh around the socket api the implementation is actually doing most stuff in users mode and it's just using the kernel mode for demultiplexing um and i think this is the way it should go in the next years so on the other hand i think seeing that both is possible should also allow an implementation to change that some at some point in time so hopefully it's possible to start with wrapper on the bsd socket api and go to some user space networking implementation at a later point in time without changing the api to the application that's what we hope to achieve thank you so much so um thank you so much to philson please give him a great round of applause