5G and Evolution of the Inter-connected Network

While there are many parameters to consider when designing the next generation network, speed is the simplest one to understand and sell to the end user.

Last week, I did a keynote at the International Telecom Sync Forum (ITSF) 2015. As an analyst keynote, I looked at how the networks are evolving and getting more complex, full of interesting options and features available for the operator to decide which ones to select.

There wont just be multiple generations of technologies existing at the same time but there will also be small cells based networks, macro networks, drones and balloons based networks and satellite based networks.

My presentation is embedded below. For any reason, if you want to download it, please fill the form at the bottom of this page and download.

Just after my keynote, I came across this news in Guardian about 'Alphabet and Facebook develop rival secret drone plans'; its an interesting read. As you may be aware Google is actively working with Sri Lanka and Indonesia for providing seamless internet access nationally.

It was nice to hear EE provide the second keynote which focused on 5G. I especially liked this slide which summarised their key 5G research areas. Their presentation is embedded below and available to download from slideshare.

5G: The Future of Mobile Communications - EE from Zahid Ghadialy

The panel discussion was interesting as well. As the conference focused on timing and synchronisation, the questions were on those topics too. I have some of them below, interested to hear your thoughts:

• Who cares about syncing the core? - Everything has moved to packets, the only reason for sync is to coordinate access points in wireless for higher level services. We have multiple options to sync the edge, why bother to sync the core at all?
• We need synchronisation to improve the user’s experience right? - Given the ever improving quality of the time-bases embedded within equipment, what exactly would happen to the user experience if synchronisation collapsed… or is good sync all about operators experience?
• IoT… and the impact on synchronisation- can we afford it? - M2M divisions of network operators make a very small fraction of the operator’s revenue, is that going to change and will it allow the required investment in sync technology that it might require?

Quick Summary of LTE Voice Summit 2015 (#LTEVoice)

Last year's summary of the LTE voice summit was very much appreciated so I have created one this year too.

The status of VoLTE can be very well summarised as can be seen in the image above.

‘VoLTE network deployment is the one of the most difficult project ever, the implementation complexity and workload is unparalleled in history’ - China Mobile group vice-president Mr.Liu Aili

Surprisingly, not many presentations were shared so I have gone back to the tweets and the pictures I took to compile this report. You may want to download the PDF from slideshare to be able to see the links. Hope you find it useful.

Related links:

• VoLTE Roaming with RAVEL (Roaming Architecture for Voice over IMS with Local Breakout)
• S8HR: Standardization of New VoLTE Roaming Architecture
• VoLTE Roaming: LBO, S8HR or HBO

Updates from the 3GPP RAN 5G Workshop - Part 3

Continuing with the updates from 5G RAN workshop, part 1 and part 2 here.

Dish network wants to have a satellite based 5G network. A recent article from Light Reading shows the following:

Dish states that there are misconceptions about what satellite technology can deliver for 5G networks. Essentially Dish says that satellites will be capable of delivering two-way communications to support 5G.

A hybrid ground and space 5G network would use small satellites that each use a "spot beam" to provide a dedicated area of two-way coverage on the ground. This is different than the old model of using one satellite with a single beam to provide a one-way service like a TV broadcast over a landmass.

Dish argues that newer, smaller satellites, equipped with the latest multi-antenna arrays (MIMO) would allow for "ubiquitous connectivity through hybrid satellite and terrestrial networks," the operator writes. In this model, satellites could connect areas that it would be hard to network otherwise like mountains and lakes.

The presentation from Dish is as follows:

Alcatel-Lucent provided a whitepaper along with the presentation. The paper provides an interesting view of 5G from their point of view. Its embedded below:

The presentation from Kyocera focused on TD-LTE which I think will play a prominent role in 5G. In case of wide channels, TD-LTE can help predict the channel accurately, which is a drawback for FDD at high frequencies. Their presentation is available here.

The presentation from NEC focussed on different technologies that will play a role in 5G. Their presentation is available here.

The final presentation we will look at this time is by the South Korean operator, KT. What is interesting to see is that in the part 1 we saw in the chairman's summary that 5G will come in two phases; Rel-15 will be phase 1 and Rel-16 will be phase 2. In the summary slide in KT's presentation, it looks like they are going to consider Rel-14 as 5G. Its not at all surprising considering that Verizon has said that they want to commercialise 5G by 2017, even though 5G will not be fully specified according to 3GPP by then. Anyway, here is the presentation by KT.

Spectrum Sharing using Licensed Shared Access (LSA)

The UK Spectrum Policy Forum has just released a report looking at Spectrum sharing approaches and in particular, Licensed Shared Access (LSA). I really like this picture shown above that summarises different approached like the DSA, LSA, etc. The report is available to download from here and is embedded below.

Related posts:

• New Spectrum Usage Paradigms for 5G

Discussion paper on '5G innovation opportunities'

Some of you may already be aware that in my day job, we have produced a discussion paper on '5G Innovation Opportunities'. The paper has two broad aims:

• to compile and create a snap shot of the diverse range of challenges and opportunities involved in developing the next phase of mobile technologies, services and applications, given the umbrella title of '5G', and 
• to identify the UK expertise and opportunities within what will undoubtedly be a global competition and collaboration to shape 5G

I am already in process of detailing the 5G RAN workshop held by 3GPP, you can read part 1 and part 2 of that; this paper complements it by providing more information about prototypes, test beds and trials. It does make an interesting read. The paper is embedded below and is available to download from here.

VoLTE Roaming: LBO, S8HR or HBO

There was an interesting discussion on different roaming scenarios in the LTE Voice Summit on 29th, 30th Sep. in London. The above picture provides a brief summary of these well known options. I have blogged about LBO/RAVEL here and S8HR here. A presentation by NTT Docomo in a GSMA webinar here provides more details on these architectures (slide 29 onwards - though it is more biased towards S8HR).

Ajay Joseph, CTO, iBasis gave an interesting presentation that highlighted the problems present in both these approaches.

In case of LBO, the biggest issue is that the home operator need to do a testing with each roaming partner to make sure VoLTE roaming works smoothly. This will be time consuming and expensive.

In case of S8HR, he provided a very good example. Imagine a VoLTE subscriber from USA is visiting Singapore. He now needs to make a phone call to someone in Indonesia (which is just next to Singapore). The flow of data would be all the way from Singapore to USA to Indonesia and back. This can introduce delays and impact QoE. The obvious advantage of S8HR is that since the call setup and media go to Home PMN (Public Mobile Network), no additional testing with the Visited PMN is required. The testing time is small and rollouts are quicker.

iBasis are proposing a solution called Hub Breakout (HBO) which would offer the best of LBO and S8HR. Each VoLTE operator would need to test their interoperability only with iBasis. Emergency calls and lawful intercept that does not work with S8HR would work with the HBO solution.

While I agree that this is a good solution, I am sure that many operators would not use this solution and there may be other solutions proposed in due course as well. Reminds me of this XKCD cartoon:

Anyway, here is the iBasis presentation:

Updates from the 3GPP RAN 5G Workshop - Part 2

I have finally got round to having a look at some more presentations on 5G from the recently concluded 3GPP RAN 5G Workshop. Part 1 of the series is here.

Panasonic introduced this concept of Sub-RAT's and Cradle-RAT's. I think it should be obvious from the picture above what they mean but you can refer to their presentation here for more details.

Ericsson has provided a very detailed presentation (but I assume a lot of slides are backup slides, only for reference). They have introduced what they call as "NX" (No compatibility constraints). This is in line to what other vendors have referred to as well that above 6GHz, for efficiency, new frame structures and waveforms would serve best. Their slides are here.



Nokia's proposal is that in the phase 1 of 5G, the 5G Access point (or 5G NodeB) would connect to the 4G Evolved Packet Core (EPC). In phase 2, both the LTE and the 5G (e)NodeB's would connect to the 5G core. Their presentation is available here.

Before we move on to the next one, I should mention that I am aware of some research that is underway, mostly by universities where they are exploring an architecture without a centralised core. The core network functionality would be distributed and some of the important data would be cached on the edge. There will be challenges to solve regarding handovers and roaming; also privacy and security issues in the latter case.

I quite like the presentation by GM research about 5G in connected cars. They make a very valid point that "Smartphones and Vehicles are similar but not the same. The presentation is embedded below.

Qualcomm presented a very technical presentation as always, highlighting that they are thinking about various future scenarios. The picture above, about phasing is in a way similar to the Ericsson picture. It also highlights what we saw in part 1, that mmW will arrive after WRC-19, in R16. Full presentation here.

The final presentation we are looking is by Mitsubishi. Their focus is on Massive MIMO which may become a necessity at higher frequencies. As the frequency goes higher, the coverage goes down. To increase the coverage area, beamforming can be used. The more the antennas, the more focused the beam could be. They have also proposed the use of SC-FDMA in DL. Their presentation is here and also embedded below.

Updates from the 3GPP RAN 5G Workshop - Part 1

3GPP held a 5G Workshop in Phoenix last week. 550 delegates and over 70 presentations contributed to the discussion, which covered the full range of requirements that will feed TSG RAN work items for the next five years. I will eventually look at all the presentations and highlight the ones that I find interesting as a part of this blog. Due to the vast number of presentations, I will split them into a few blog posts.

Lets start with the chairman summary. The chair highlighted three high level use cases that 5G needs to address (This has been highlighted in many presentations, see here for example):

• Enhanced Mobile Broadbandare 
• Massive Machine Type Communications
• Ultra-reliable and Low Latency Communications

As can be seen in the picture above, 3GPP is planning to split the 5G work into two phases. Phase 1 (Rel-15) will look at a subset of requirements that are important for the commercial needs of the day. Phase 2 (Rel-16) will look at more features, use cases, detailed requirements, etc.

Here is the chair summary of the workshop:

The presentation (RWS-150002) from Motorola/Lenovo highlighted the need to handle different spectrum. For sub-6GHz, the existing air interface could work with slight modifications. For spectrum between 6GHz and 30GHz, again a similar air interface like 4G may be good enough but for above 30GHz, there is a need for new one die to phase noise.

The presentation by CATT or China Academy of Telecommunication Technology (RWS-150003) is quite interesting and is embedded below. They also propose Pattern Division Multiple Access (PDMA).

Orange (RWS-150004) has definitely put a thought into what good 5G would be. Their presentation is embedded below too:

The presentation from Huawei (RWS-150006) introduced the concept of Unified Air Interface, UAI.



They presentation also explains the concept of Adaptive Frame structures and RAN slicing very well. For those who may be wondering, uMTC stands for ultra-reliable MTC and mMTC stands for massive MTC. RAN slicing enables the RAN to be partitioned such that a certain amount of carriers are always dedicated to a certain services independently of other services. This ensures that the service in the slice is always served reliably.

The final presentation is the vision and priorities by 5GPPP as follows:

3GPP Release-13 whitepapers and presentations

With 3GPP Release-13 due early/mid next year, there has been a flurry of presentations and whitepapers on this topic. This post provides some of these. I will try and maintain a list of whitepapers/presentations as part of this post as and when released.

1. June 2015: LTE Release 13 and road to 5G - Presented by Dino Flore, Chairman of 3GPP RAN, (Qualcomm Technologies Inc.)

2. Sep 2015: Executive Summary - Inside 3GPP Release 13 by 4G Americas

3. June 2015: Mobile Broadband Evolution Towards 5G: 3GPP Rel-12 & Rel-13 and Beyond by 4G Americas

4. April 2015: LTE release 13 – expanding the Networked Society by Ericsson

HetNets and Ultra Dense Networks

When I did my 5G presentation back in Feb., I explained about Ultra Dense Networks (UDN) that will be a main feature of future traffic hotspots. I have also blogged about Qualcomm having tested 1000 small cells in a square km. Some operators are already running out of spectrum with traditional deployments in hotspots. They are already making their cells smaller (but not yet using Small cells) thereby having less users in each cell. This may not be enough so the approach likely to be taken is:

• Offload to WiFi
• Aggregate WiFi with LTE (different approaches including LTE-U, LAA and LWA)
• Use Small cells and C-RAN
• Multi technology Carrier Aggregation
• Beamforming (and massive MIMO)

The above picture is from a presentation (embedded below) by ZTE in the LTE World Summit. Its a good attempt to show different technologies, the year they are expected to go mainstream, whether they are TDD or FDD and if they will form part of 5G.

Anyway, here is the presentation. There is some interesting information on C-RAN, D-RAN results and fronthaul too.