Saturday, 7 January 2017

New LTE UE Categories (Downlink & Uplink) in Release-13

Just noticed that the LTE UE Categories have been updated since I last posted here. Since Release-12 onwards, we now have a possibility of separate Downlink (ue-CategoryDL) and Uplink (ue-CategoryUL) categories.

From the latest RRC specifications, we can see that now there are two new fields that can be present ue-CategoryDL and ue-CategoryUL.

An example defined here is as follows:

Example of RRC signalling for the highest combination
UE-EUTRA-Capability
   ue-Category = 4
      ue-Category-v1020 = 7
         ue-Category-v1170 = 10
            ue-Category-v11a0 = 12
               ue-CategoryDL-r12 = 12
               ue-CategoryUL-r12 = 13
                  ue-CategoryDL-v1260 = 16

From the RRC Specs:

  • The field ue-CategoryDL is set to values m1, 0, 6, 7, 9 to 19 in this version of the specification.
  • The field ue-CategoryUL is set to values m1, 0, 3, 5, 7, 8, 13 or 14 in this version of the specification.

3GPP TS 36.306 section 4 provides much more details on these UE categories and their values. I am adding these pictures from the LG space website.



More info:



Saturday, 10 December 2016

Free Apps for Field Testing

People who follow me on Twitter may have often noticed I put photos when I am doing surveys, field testing, debugging, etc. In the good old days we often had to carry a lot of different kind of specialised test equipment to do basic measurements. Nowadays a lot of these can be done with the help of free apps on Android phones. The best tool that can provide a great amount of info is Qualcomm's QXDM but its really expensive.

Here are a few tools that I use. If you have one that I havent listed below, please add it in comments.


The screen shot shows the main tools along with my favourite, SpeedTest. While I agree that Speedtest is not the most reliable approach to speed of your connection, I think its the most standard one being used.


WiFi Analyzer is another great app that can be used at home and other locations where people complain about not getting good WiFi speeds. I have been at locations where the 2.4GHz is absolutely packed with APs. 5GHz is also getting busier, though there are still a lot of free channels.


G-NetTrack Lite is a great tool to keep track of the cells you have been visiting. In case you are driving this can collect a lot of valuable info. The paid version, G-NetTrack Pro can collect the info in form of a map that can be used for offline viewing with the help of Google Earth.


I use LTE Discovery mainly for finding the band I am currently camped on. It would be great if a tool can give the exact frequency and earfcn but the band is good enough too. I was once in a situation where I could see two different cells but they had the same PCI. Only after using this, I figured out they were on different bands.


Finally, Network Cell Info Lite gives neighbour cells which can often be useful. I am not sure of these are the neighbours from System Info or from Measurement Control messages sent by network or just something like Detected cells that the phone sees around.

Pind and IPConfig are other tools that can come handy sometimes.

Are there any other tools that you like? Please share using comments.

Free Apps for Field Testing - Part 2

Sunday, 4 December 2016

5G, Hacking & Security


It looks like devices that are not manufactures with security and privacy in mind are going to be the weakest link in future network security problems. I am sure you have probably read about how hacked cameras and routers enabled a Mirai botnet to take out major websites in October. Since then, there has been no shortage of how IoT devices could be hacked. In fact the one I really liked was 'Researchers hack Philips Hue lights via a drone; IoT worm could cause city blackout' 😏.


Enter 5G and the problem could be be made much worse. With high speed data transfer and signalling, these devices can create an instantaneous attack on a very large scale and generating signalling storm that can take a network down in no time.

Giuseppe TARGIA, Nokia presented an excellent summary of some of these issues at the iDate Digiworld Summit 2016. His talk is embedded below:



You can check out many interesting presentations from the iDate Digiworld Summit 2016 on Youtube and Slideshare.

Related posts:


Wednesday, 23 November 2016

Facebook's Attempt to Connect the Unconnected

I am sure that by now everyone is aware of Facebook's attempt to connect the people in rural and remote areas. Back in March they published the State of Connectivity report highlighting that there are still over 4 billion people that are unconnected.


The chart above is very interesting and shows that there are still people who use 2G to access Facebook. Personally, I am not sure if these charts take Wi-Fi into account or not.

In my earlier post in the Small Cells blog, I have made a case for using Small Cells as the best solution for rural & remote coverage. There are a variety of options for power including wind turbines, solar power and even the old fashioned diesel/petrol generators. The main challenge is sometimes the backhaul. To solve this issue Facebook has been working on its drones as a means of providing the backhaul connectivity.


Recently Facebook held its first Telco Infra Project (TIP) Summit in California. The intention was to bring the diverse set of members (over 300 as I write this post) in a room, discuss ideas and ongoing projects.


There were quite a few interesting talks (videos available here). I have embedded the slides and the talk by SK Telecom below but before I that I was to highlight the important point  made by AMN.


As can be seen in the picture above, technology is just one of the challenges in providing rural and remote connectivity. There are other challenges that have to be considered too.

Embedded below is the talk provided by Dr. Alex Jinsung Choi,  CTO, SK Telecom and TIP Chairman and the slides follow that.



For more info, see:
Download the TIP slides from here.

Thursday, 17 November 2016

5G, Debates, Predictions and Stories

This post contains summary of three interesting events that took place recently.


CW (Cambridge Wireless) organised a couple of debates on 5G as can be seen from the topics above. Below is the summary video and twitter discussion summary/story.





The second story is from 'The Great Telco Debate 2016' organised by TM forum


I am not embedding the story but for anyone interested, they can read the twitter summary here: https://storify.com/zahidtg/the-great-telco-debate-2016



Finally, it was 'Predictions: 2017 and Beyond', organised by CCS Insight. The whole twitter discussion is embedded below.


Saturday, 12 November 2016

Verizon's 5G Standard

Earlier this year I wrote a Linkedin post on how operators are setting a timetable for 5G (5G: Mine is bigger than yours) and recently Dean Bubley of Disruptive Analysis wrote a similar kind of post also on Linkedin with a bit more detail (5G: Industry Politics, Use-Cases & a Realistic Timeline)


Some of you may be unaware that the US operator Verizon has formed 'Verizon 5G Technology Forum' (V5GTF) with the intention of developing the first set of standards that can also influence the direction of 3GPP standardization and also provide an early mover advantage to itself and its partners.

The following from Light Reading news summarizes the situation well:

Verizon has posted its second round of work with its partners on a 5G specification. The first round was around the 5G radio specification; this time the work has been on the mechanics of connecting to the network. The operator has been working on the specification with Cisco Systems Inc., Ericsson AB, Intel Corp., LG Electronics Inc., Nokia Corp., Qualcomm Inc. and Samsung Corp. via the 5G Technology Forum (V5GTF) it formed late in 2015.

Sanyogita Shamsunder, director of strategy at Verizon, says that the specification is "75% to 80% there" at least for a "fixed wireless use case." Verizon is aiming for a "friendly, pre-commercial launch" of a fixed wireless pilot in 2017, Koeppe notes.

Before we go further, lets see this excellent video by R&S wherein Andreas Roessler explains what Verizon is up to:



Verizon and SKT are both trying to be the 5G leaders and trying to roll out a pre-standard 5G whenever they can. In fact Qualcomm recently released a 28 GHz modem that will be used in separate pre-standard 5G cellular trials by Verizon and Korea Telecom

Quoting from the EE times article:

The Snapdragon X50 delivers 5 Gbits/second downlinks and multiple gigabit uplinks for mobile and fixed-wireless networks. It uses a separate LTE connection as an anchor for control signals while the 28 GHz link delivers the higher data rates over distances of tens to hundreds of meters.

The X50 uses eight 100 MHz channels, a 2x2 MIMO antenna array, adaptive beamforming techniques and 64 QAM to achieve a 90 dB link budget. It works in conjunction with Qualcomm’s SDR05x mmWave transceiver and PMX50 power management chip. So far, Qualcomm is not revealing more details of modem that will sample next year and be in production before June 2018.

Verizon and Korea Telecom will use the chips in separate trials starting late next year, anticipating commercial services in 2018. The new chips mark a departure from prototypes not intended as products that Qualcomm Research announced in June.

Korea Telecom plans a mobile 5G offering at the February 2018 Winter Olympics. Verizon plans to launch in 2018 a less ambitious fixed-wireless service in the U.S. based on a specification it released in July. KT and Verizon are among a quartet of carriers that formed a group in February to share results of early 5G trials.

For its part, the 3GPP standards group is also stepping up the pace of the 5G standards efforts it officially started earlier this year. It endorsed last month a proposal to consider moving the date for finishing Phase I, an initial version of 5G anchored to LTE, from June 2018 to as early as December 2017, according to a recent Qualcomm blog.

Coming back to Verizon's 5G standard, is it good enough and compatible with 3GPP standards? The answer right now seems to be NO.


The following is from Rethink Wireless:

The issue is that Verizon’s specs include a subcarrier spacing value of 75 kHz, whereas the 3GPP has laid out guidelines that subcarrier spacing must increase by 30 kHz at a time, according to research from Signals Research Group. This means that different networks can work in synergy if required without interfering with each other.

Verizon’s 5G specs do stick to 3GPP requirements in that it includes MIMO and millimeter wave (mmWave). MmWave is a technology that both AT&T and Verizon are leading the way in – which could succeed in establishing spectrum which is licensed fairly traditionally as the core of the US’s high frequency build outs.

A Verizon-fronted group recently rejected a proposal from AT&T to push the 3GPP into finalizing an initial 5G standard for late 2017, thus returning to the original proposed time of June 2018. Verizon was supported by Samsung, ZTE, Deutsche Telecom, France Telecom, TIM and others, which were concerned the split would defocus SA and New Radio efforts and even delay those standards being finalized.

Verizon has been openly criticized in the industry, mostly by AT&T (unsurprisingly), as its hastiness may lead to fragmentation – yet it still looks likely to beat AT&T to be the first operator to deploy 5G, if only for fixed access.

Verizon probably wants the industry to believe that it was prepared for eventualities such as this – prior to the study from Signal Research Group, the operator said its pre-standard implementation will be close enough to the standard that it could easily achieve full compatibility with simple alterations. However, Signals Research Group’s president Michael Thelander has been working with the 3GPP since the 5G standard was birthed, and he begs to differ.

Thelander told FierceWireless, “I believe what Verizon is doing is not hardware-upgradeable to the real specification. It’s great to be trialing, even if you define your own spec, just to kind of get out there and play around with things. That’s great and wonderful and hats off to them. But when you oversell it and call it 5G and talk about commercial services, it’s not 5G. It’s really its own spec that has nothing to do with Release 16, which is still three years away. Just because you have something that operates in millimeter wave spectrum and uses Massive MIMO and OFDM, that doesn’t make it a 5G solution.”

Back in the 3G days, NTT Docomo was the leader in standards and it didn't have enough patience to wait for 3GPP standards to complete. As a result it released its first 3G network called FOMA (Freedom of Mobile Access) based on pre-standard version of specs. This resulted in handset manufacturers having to tweak their software to cope with this version and it suffered from economy of scale. Early version of 3G phones were also not able to roam on the Docomo network. In a way, Verizon is going down the same path.

While there can be some good learning as a result of this pre-5G standard, it may be a good idea not to get too tied into it. A standard that is not compliant will not achieve the required economy of scale, either with handsets or with dongles and other hotspot devices.


Related posts:



Sunday, 6 November 2016

LTE, 5G and V2X

3GPP has recently completed the Initial Cellular V2X standard. The following from the news item:

The initial Cellular Vehicle-to-Everything (V2X) standard, for inclusion in the Release 14, was completed last week - during the 3GPP RAN meeting in New Orleans. It focuses on Vehicle-to-Vehicle (V2V) communications, with further enhancements to support additional V2X operational scenarios to follow, in Release 14, targeting completion during March 2017.
The 3GPP Work Item Description can be found in RP-161894.
V2V communications are based on D2D communications defined as part of ProSe services in Release 12 and Release 13 of the specification. As part of ProSe services, a new D2D interface (designated as PC5, also known as sidelink at the physical layer) was introduced and now as part of the V2V WI it has been enhanced for vehicular use cases, specifically addressing high speed (up to 250Kph) and high density (thousands of nodes).

...


For distributed scheduling (a.k.a. Mode 4) a sensing with semi-persistent transmission based mechanism was introduced. V2V traffic from a device is mostly periodic in nature. This was utilized to sense congestion on a resource and estimate future congestion on that resource. Based on estimation resources were booked. This technique optimizes the use of the channel by enhancing resource separation between transmitters that are using overlapping resources.
The design is scalable for different bandwidths including 10 MHz bandwidth.
Based on these fundamental link and system level changes there are two high level deployment configurations currently defined, and illustrated in Figure 3.
Both configurations use a dedicated carrier for V2V communications, meaning the target band is only used for PC5 based V2V communications. Also in both cases GNSS is used for time synchronization.
In “Configuration 1” scheduling and interference management of V2V traffic is supported based on distributed algorithms (Mode 4) implemented between the vehicles. As mentioned earlier the distributed algorithm is based on sensing with semi-persistent transmission. Additionally, a new mechanism where resource allocation is dependent on geographical information is introduced. Such a mechanism counters near far effect arising due to in-band emissions.
In “Configuration 2” scheduling and interference management of V2V traffic is assisted by eNBs (a.k.a. Mode 3) via control signaling over the Uu interface. The eNodeB will assign the resources being used for V2V signaling in a dynamic manner.

5G Americas has also published a whitepaper on V2X Cellular Solutions. From the press release:

Vehicle-to-Everything (V2X) communications and solutions enable the exchange of information between vehicles and much more - people (V2P), such as bicyclists and pedestrians for alerts, vehicles (V2V) for collision avoidance, infrastructure (V2I) such as roadside devices for timing and prioritization, and the network (V2N) for real time traffic routing and other cloud travel services. The goal of V2X is to improve road safety, increase the efficiency of traffic, reduce environmental impacts and provide additional traveler information services. 5G Americas, the industry trade association and voice of 5G and LTE for the Americas, today announced the publication of a technical whitepaper titled V2X Cellular Solutions that details new connected car opportunities for the cellular and automotive industries.




The whitepaper describes the benefits that Cellular V2X (C-V2X) can provide to support the U.S. Department of Transportation objectives of improving safety and reducing vehicular crashes. Cellular V2X can also be instrumental in transforming the transportation experience by enhancing traveler and traffic information for societal goals.

C-V2X is part of the 3GPP specifications in Release 14. 3GPP announced the completion of the initial C-V2X standard in September 2016. There is a robust evolutionary roadmap for C-V2X towards 5G with a strong ecosystem in place. C-V2X will be a key technology enabler for the safer, more autonomous vehicle of the future.

The whitepaper is embedded below:




Related posts:
Further Reading:



Saturday, 29 October 2016

M2M vs IoT

This post is for mainly for my engineering colleagues. Over the years I have had many discussions to explain the difference between Machine-to-Machine (M2M) or Machine Type Communication (MTC) as 3GPP refers to them and the Internet of Things (IoT). Even after explaining the differences, I am often told that this is not correct. Hence I am putting this out here. Please feel free to express your views in the comments section.


Lets take an example of an office with 3 floors. Lets assume that each floor has a coffee machine like the one in this picture or something similar. Lets assume different scenarios:

Scenario 1: No connectivity
In this case a facilities person has to manually go to each of the floor and check if there are enough coffee beans, chocolate powder, milk powder, etc. He/She may have to do this say 3-4 times a day.

Scenario 2: Basic connectivity (M2M)
Lets say the coffee machine has basic sensors so it can send some kind of notification (on your phone or email or message, etc.) whenever the coffee beans, chocolate powder, milk powder, etc., falls below a certain level. In some cases you may also be able to check the levels using some kind of a app on your phone or computer. This is an example of M2M

Scenario 3: Advanced connectivity (IoT)
Lets say that the coffee machine is connected to the office system and database. It knows which employees come when and what is their coffee/drinks consumption pattern. This way the machine can optimize when it needs to be topped up. If there is a large meeting/event going on, the coffee machine can even check before the breaks and indicate in advance that it needs topping up with beans/chocolate/milk/etc.

Scenario 4: Intelligent Devices (Advanced IoT)
If we take the coffee machine from scenario 3 and add intelligence to it, it can even know about the inventory. How much of coffee beans, chocolate powder, milk powder, etc is in stock and when would they need ordering again. It can have an employee UI (User Interface) that can be used by employees to give feedback on which coffee beans are more/less popular or what drinks are popular. This info can be used by the machines to order the supplies, taking into account the price, availability, etc.

In many cases, API's would be available for people to build services on top of the basic available services to make life easier. Someone for example can build a service that if a cup is already at the dispenser and has been there for at least 2 minutes (so you know its not being used by someone else) then the person can choose/order their favourite drink from their seat so he/she doesn't have to wait for 30 seconds at the machine.

If you think about this further you will notice that in this scenario the only requirement for the human is to clean the coffee machine, top it up, etc. In future these can be automated with robots carrying out these kinds of jobs. There would be no need for humans to do these menial tasks.


I really like this slide from InterDigital as it captures the difference between M2M and IoT very well, especially in the light of the discussion above.

With the current M2M, we have:

  • Connectivity: connection for machines;
  • Content: massive raw data from things;

IoT is Communication to/from things which offer new services via cloud / context / collaboration / cognition technologies.

With evolution to IoT, we have:
  • Cloud: cloud service and XaaS (Everything as a Service) for IoT;
  • Context: context-aware design;
  • Collaboration: collaborative services;
  • Cognition: semantics and autonomous system adjustment
Let me know if you agree. 

Sunday, 23 October 2016

VoLTE Operator Case Study from LTE Voice Summit


Phil Sheppard, Director of Network Strategy & Architecture, Three UK was the keynote speaker of LTE Voice Summit held in London this month. Its been over a year that Three launched its VoLTE service in the 800MHz band. In fact recently, it has started showing adverts with Maisie Williams (Arya Stark from Game of Thrones) fighting black spots (not spots) with 4G Super-Voice.



As I highlighted in the LTEVoice 2015 summary where China Mobile group vice-president Mr.Liu Aili admitted "VoLTE network deployment is the one of the most difficult project ever, the implementation complexity and workload is unparalleled in history", Three UK's experience wasn't very different. Quoting from ThinkSmallCell summary of the event:
It was a huge project, the scope far exceeding original expectations and affecting almost every part of their operations.  They spent 22,245 man days (excluding vendor staff time) – more than 100 man years of effort – mostly involved with running huge numbers of test cases on the network and devices.

There are some other interesting bits from the different summaries that are provided in references below but here are few things I found of interest with regards to Three UK VoLTE deployment:
  • 170 million voice calls minutes have used VoLTE since the launch in Sept 2015
  • Only devices that can support VoLTE and 800MHz are allowed to camp on 800MHz band. This is to avoid disappointment with CS Fallback
  • There are plans to roll out VoLTE in other bands too once all niggles are ironed out in the 800MHz band.

Here is the presentation from 3 UK:



Blog posts summarizing LTEVoice 2016:

Related posts: