This video starts with theory of Carrier Aggregation and then moves to UE log analysis for CA. It also discusses, cross carrier scheduling and impact of CA on various layers of LTE protocol stack.
Very good video to understand CA !! Carrier Aggregation Basics Explained in very simple way. The best part is the tutorial is very practical as theory has been explained with 3GPP IEs. Generally this co-relation is the toughest part
There are test case scenarios, in which My Secondary cell (y) becomes primary cell (x), and Primary(x) becomes secondary cell(y) and then the current secondary cell gets removed after data transmission completed. How we can see that in log?
Hello, great work "D"ude :) All the topics in your channel are explained well and in very simplified manner. Keep up the good work.Looking forward for more.
Tks a lot. So in supportedBandcombination, such as 1A-3A in your video, please more details about DL and UL, as I saw band 1 support DL class A, and band 3 support both class A in UL and DL --> so in this example: support CA 1A-3A in DL . How about UL in band 3 and band 1 ?
For bandwidth combination set 0 , UE does not send IE....What does "IE" refers to? Also is this band combination set fixed for 0,1 and 2 that is 8 ,4 and 2 or it is just an arbitrary example
Very nice explanation.. with clear understanding... Can you upload presentation for LTE-MIMO technology with UE log snippets... ? can you let me apart from support of rel-10 and onward release, is any limitations for using CA ?? please let me know how CA relates to Dual/Three carrier cell in HSPA ???
Thanks Umesh for feedback! 1) Okay, I will try to cover MIMO with log analysis in coming days. 2) As such there is no limitation, but rel-10 is not the only thing needed. UE's physical layer should also support carrier aggregation. So, list of UE's capabilities sent by UE in UE capability message play a major role for allocation of CA. That is why, I have discussed this message in detail in this video. 3) It is very difficult to do one on one comparison, but they are similar as both of them allow UE to get data on a wider channel bandwidth.
Excellent video, I like the way you explain this topic, very good, thanks a lot. I am wondering about the scenario to test CA, could you please let me know one or two ways to test/verify CA ? what tools are needed ? what can I do to create enough traffic to force the UE to do CA ? In advance thanks again and keep up the good job your are doing.
Thanks for such a positive feedback. It really motivates me. First condition for CA is that network should have configured it. So, first of all search for a CA area. For this searching you need CA capable mobile. Mostly, operators configure CA in city centers or highly populated areas. Data threshold has nothing to do with CA allocated. Only thing needed is that secondary cell should meet the measurement criterion. If you have a active data flow and second cell is added to the UE, eNodeB will activate the secondary cell to make data completion quicker. You can check activation of secondary cell either by using the suitable AT command. I do not remember the command at this moment. Or you can analyse RRC logs to confirm activation of secondary cell. Hope this will help.
Hi Umesh..by mistake youtube suspended my channel in feb..I submitted a request to reinstate it..they admitted that by mistake they suspended my channel and unsuspended it today. It was a very bad experience for me too..rather it was a nightmare for me..I can understand what subscribers of this channel would have gone through ..but now everything is fine..I am happy :)
Actually no single book will tell you all. I like “Theory to practice” for basics. Don’t remember the exact name. But for latest features such as CA, MIMO internet is the best resource.
Thank you for this brief explanation!Is CA is used in LTE or LTEAdvanced?If it is used for both ,what the difference between CA IN LTE and CA in LTEADVANCED?Thanks in advance
Hi, Your videos are very helpful and very real time experience. I have a question regarding the Bandwidth Combination Set. For CA_1A_8A, why is it not possible for both bands to have combinations 1.4MHz & 1.4MHz, 3MHz & 3MHz? Could you please explain. In simple, why not other combinations possible between these 2 bands BW? I did understand the part "A" refers to RB's less than 100. So in that case, why not Band 1's 3MHz and Band 8's 3MHz.
I think I understood after watching it many times. Is it because of 3GPP standards " Table 5.6A 1-2 "from 36.101". I also read the below line in a CA document " For practical purposes, 3GPP limits the number of inter-band combinations defined to those required by operators".
Hi Nevsky, thanks for watching the video!! Even, I do not know on basis these combinations are made. But all the possible combinations of bandwidth are defined in the 3GPP specification. You can go to 36.101 and see all kind of combinations such as band combinations, bandwidth combinations etc. for CA. I think as CA is a physical layer concept, so to limit complexities at Physical layer 3GPP has limited the possible combinations. Your research also says the same. But it is nice to see such interesting question. Keep coming!!
It's really nice making off it rather reading hours together.... Actually I'm RF DT engineer but I'm very intended to know about this protocol stack.... Well don't mind I have one doubt that if there is a 100mb of data in a pipe line we have 100 users now each user get how much about of data..?? Please tell me answer... Thanks for making clips..
Firstly, thanks for your feedback. It really matters to me! It is not possible to answer this question by any means. As there are many factors affecting data rate for a given user so data rate for each user will vary. Few of these factors are UE capability and Radio conditions. Theoretically, if all factors are same, available bandwidth will be equally divided among all UEs. MAC layer of eNodeB dynamically allocates resources to each UE based on these varying factors . Please refer to my video on data rate calculation. This video will make things crystal clear. Happy watching 😀
There is limitation on number of UEs scheduled per TTI (like 4,6,8,16). Suppose 8 UE per TTI is configured in enodeB. So eNodeB will allocated all the resources among 8 UEs only. Now your next question is how eNodeB decides to allocate how much resources to all UEs. That actually depends on scheduler algorithm. If eNodeB is running on RoundRobin Scheduler then all 8 users will get equal resources, which is not the case generally. So eNodeB manages quality of service and uses different types of QoS scheduler mechanism that calculates priority for all UEs based on Radio conditions and data in buffer as described by Pandari in Comments. Further those resources are divided among 8 users based on priority. In next tti further 8 users can be selected based on priority.
Hello, Is it right that we shouldn't take the secondary carrier component's throughput on the Physical layer, rather it should be taken from PDCP layer. (For measurement) Please explain
Hi Zeeshan, I did not get your question fully. What is your opinion? Why shouldn't we take throughput from Physical layer and why should be take it from PDCP layer? Please elaborate.
Actually, I am trying to view my TDD 2nd carrier TP, on tems investigation. And I have seen a huge difference b/w PUSH TP and PDCP TP. Normally we take the Phy layer TP, and there is almost no difference b/w the two layesr's. but as I come to 2nd carrier, it shows bugged kind of values on Phy layer
what does this ca combination define here? CA_3A { bandEUTRA-r10 3, bandParametersUL-r10 { { ca-BandwidthClassUL-r10 a } }, bandParametersDL-r10 { { ca-BandwidthClassDL-r10 a, supportedMIMO-CapabilityDL-r10 twoLayers } } } },
@@dineshd7687 but class A signifies that CA_3A. But there is no single frequency ca he also tells in video that CA_25A will not be mentioned since ca is not supported with single carrier
Hello Sir Very nice explanation on CA in simple ways to understand. How can we know UE 4*4 or 2*2 MIMO enabled or disabled from the message from UE capability information or UE capability enquiry that enodeB received.