5G, NFV and Network Slicing

5G networks have multifaceted requirements where the network needs to be optimised for data rate, delay and connection numbers. While some industry analysts suspect that these requirements cannot be met by a single network, vendors suggest that Network Slicing will allow all these requirements to be met by a single network.

Ericsson's whitepaper provides a good definition of what network slicing means:

A logical instantiation of a network is often called a network slice. Network slices are possible to create with both legacy platforms and network functions, but virtualization technologies substantially lower barriers to using the technology, for example through increased flexibility and decreased costs.

...

Another aspect of management and network slicing is setting up separate management domains for different network slices. This may allow for completely separate management of different parts of the network that are used for different purposes. Examples of use cases include mobile virtual network operators (MVNOs) and enterprise solutions. This kind of network slice would, in current Evolved Packet Core (EPC) networks, only cover the PDN gateway (PGW) and the policy control resource function (PCRF). However, for machine type communication (MTC) and machine-tomachine (M2M) solutions, it is likely that it would also cover the Mobile Management Entities (MMEs) and Serving Gateways (SGWs).

NGMN came out with the 5G whitepaper which touched on this subject too: 

Figure above illustrates an example of multiple 5G slices concurrently operated on the same infrastructure. For example, a 5G slice for typical smartphone use can be realized by setting fully-fledged functions distributed across the network. Security, reliability and latency will be critical for a 5G slice supporting automotive use case. For such a slice, all the necessary (and potentially dedicated) functions can be instantiated at the cloud edge node, including the necessary vertical application due to latency constraints. To allow on-boarding of such a vertical application on a cloud node, sufficient open interfaces should be defined. For a 5G slice supporting massive machine type devices (e.g., sensors), some basic C-plane functions can be configured, omitting e.g., any mobility functions, with contentionbased resources for the access. There could be other dedicated slices operating in parallel, as well as a generic slice providing basic best-effort connectivity, to cope with unknown use cases and traffic. Irrespective of the slices to be supported by the network, the 5G network should contain functionality that ensures controlled and secure operation of the network end-to-end and at any circumstance.

Netmanias has a detailed article on this topic which is quite interesting too, its available here.

Recently, South Korean operator SK Telecom and Ericsson concluded a successful trial of this technology, see here. Ericsson is also working with NTT Docomo on 5G including network slicing, see here.

'Mobile Edge Computing' (MEC) or 'Fog Computing' (fogging) and 5G & IoT

Picture Source: Cisco

The clouds are up in the sky whereas the fog is low, on the ground. This is how Fog Computing is referred to as opposed to the cloud. Fog sits at the edge (that is why edge computing) to reduce the latency and do an initial level of processing thereby reducing the amount of information that needs to be exchanged with the cloud.

The same paradigm is being used in case of 5G to refer to edge computing, which is required when we are referring to 1ms latency in certain cases.

As this whitepaper from Ovum & Eblink explains:

Mobile Edge Computing (MEC): Where new processing capabilities are introduced in the base station for new applications, with a new split of functions and a new interface between the baseband unit (BBU) and the remote radio unit (RRU).
...
Mobile Edge Computing (MEC) is an ETSI initiative, where processing and storage capabilities are placed at the base station in order to create new application and service opportunities. This new initiative is called “fog computing” where computing, storage, and network capabilities are deployed nearer to the end user.

MEC contrasts with the centralization principles discussed above for C-RAN and Cloud RAN. Nevertheless, MEC deployments may be built upon existing C-RAN or Cloud RAN infrastructure and take advantage of the backhaul/fronthaul links that have been converted from legacy to these new centralized architectures.

MEC is a long-term initiative and may be deployed during or after 5G if it gains support in the 5G standardization process. Although it is in contrast to existing centralization efforts, Ovum expects that MEC could follow after Cloud RAN is deployed in large scale in advanced markets. Some operators may also skip Cloud RAN and migrate from C-RAN to MEC directly, but MEC is also likely to require the structural enhancements that C-RAN and Cloud RAN will introduce into the mobile network.

The biggest challenge facing MEC in the current state of the market is its very high costs and questionable new service/revenue opportunities. Moreover, several operators are looking to invest in C-RAN and Cloud RAN in the near future, which may require significant investment to maintain a healthy network and traffic growth. In a way, MEC is counter to the centralization principle of Centralized/Cloud RAN and Ovum expects it will only come into play when localized applications are perceived as revenue opportunities.

And similarly this Interdigital presentation explains:

Extends cloud computing and services to the edge of the network and into devices. Similar to cloud, fog provides network, compute, storage (caching) and services to end users. The distinguishing feature of Fog reduces latency & improves QoS resulting in a superior user experience

Here is a small summary of the patents with IoT and Fog Computing that has been flied.

Cellular IoT (CIoT) or LoRa?

Back in September, 3GPP reached a decision to standardise NarrowBand IOT (NB-IOT). Now people familiar with the evolution of LTE-A UE categories may be a bit surprised with this. Upto Release-11, the lowest data rate device was UE Cat-1, which could do 10Mbps in DL and 5Mbps in UL. This was power hungry and not really that useful for low data rate sensor devices. Then we got Cat-0 as part of Release-12 which simplified the design and have 1Mbps in DL & UL.

Things start to become a bit complex in Release-13. The above picture from Qualcomm explains the evolution and use cases very well. However, to put more details to the above picture, here is some details from the 4G Americas whitepaper (embedded below)

In support of IoT, 3GPP has been working on all several related solutions and generating an abundance of LTE-based and GSM-based proposals. As a consequence, 3GPP has been developing three different cellular IoT standard- solutions in Release-13:

• LTE-M, based on LTE evolution
• EC-GSM, a narrowband solution based on GSM evolution, and
• NB-LTE, a narrowband cellular IoT solution, also known as Clean Slate technologies

However, in October 2015, the 3GPP RAN body mutually agreed to study the combination of the two different narrowband IoT technical solutions, EC-GSM and NB-LTE, for standardization as a single NB-IoT technology until the December 2015 timeframe. This is in consideration of the need to support different operation modes and avoid divided industry support for two different technical solutions. It has been agreed that NB-IoT would support three modes of operation as follows:

• ‘Stand-alone operation’ utilizing, for example, the spectrum currently being used by GERAN systems as a replacement of one or more GSM carriers,
• ‘Guard band operation’ utilizing the unused resource blocks within a LTE carrier’s guard-band, and
• ‘In-band operation’ utilizing resource blocks within a normal LTE carrier.

Following is a brief description of the various standard solutions being developed at 3GPP by October 2015:

LTE-M: 3GPP RAN is developing LTE-Machine-to-Machine (LTE-M) specifications for supporting LTE-based low cost CIoT in Rel-12 (Low-Cost MTC) with further enhancements planned for Rel-13 (LTE eMTC). LTE-M supports data rates of up to 1 Mbps with lower device cost and power consumption and enhanced coverage and capacity on the existing LTE carrier.

EC-GSM: In the 3GPP GERAN #62 study item “Cellular System Support for Ultra Low Complexity and Low Throughput Internet of Things”, narrowband (200 kHz) CIoT solutions for migration of existing GSM carriers sought to enhance coverage by 20 dB compared to legacy GPRS, and achieve a ten year battery life for devices that were also cost efficient. Performance objectives included improved indoor coverage, support for massive numbers of low-throughput devices, reduced device complexity, improved power efficiency and latency. Extended Coverage GSM (EC-GSM) was fully compliant with all five performance objectives according to the August 2015 TSG GERAN #67 meeting report. GERAN will continue with EC-GSM as a work item within GERAN with the expectation that standards will be frozen by March 2016. This solution necessarily requires a GSM network.

NB-LTE: In August 2015, work began in 3GPP RAN Rel-13 on a new narrowband radio access solution also termed as Clean Slate CIoT. The Clean Slate approach covers the Narrowband Cellular IoT (NB-CIoT), which was the only one of six proposed Clean Slate technologies compliant against a set of performance objectives (as noted previously) in the TSG GERAN #67 meeting report and will be part of Rel-13 to be frozen in March 2016. Also contending in the standards is Narrowband LTE Evolution (NB-LTE) which has the advantage of easy deployment across existing LTE networks.

Rel-12 introduces important improvements for M2M like lower device cost and longer battery life. Further improvements for M2M are envisioned in Rel-13 such as enhanced coverage, lower device cost and longer battery life. The narrowband CIoT solutions also aim to provide lower cost and device power consumption and better coverage; however, they will also have reduced data rates. NB CleanSlate CIoT is expected to support data rates of 160bps with extended coverage.

Table 7.1 provides some comparison of the three options to be standardized, as well as the 5G option, and shows when each release is expected to be finalized.

Another IoT technology that has been giving the cellular IoT industry run for money is the LoRa alliance. I blogged about LoRa in May and it has been a very popular post. A extract from a recent article from Rethink Research as follows:

In the past few weeks, the announcements have been ramping up. Semtech (the creator of the LoRa protocol itself, and the key IP owner) has been most active, announcing that The Lace Company, a wireless operator, has deployed LoRa network architecture in over a dozen Russian cities, claiming to cover 30m people over 9,000km2. Lace is currently aiming at building out Russian coverage, but will be able to communicate to other LoRa devices over the LoRa cloud, as the messages are managed on cloud servers once they have been transmitted from end-device to base unit via LoRaWAN.

“Our network allows the user to connect to an unlimited number of smart sensors,” said Igor Shirokov, CEO of Lace Ltd. “We are providing connectivity to any device that supports the open LoRaWAN standard. Any third party company can create new businesses and services in IoT and M2M market based on our network and the LoRaWAN protocol.”

Elsewhere, Saudi Arabian telco Du has launched a test LoRa network in Dubai, as part of a smart city test project. “This is a defining moment in the UAE’s smart city transformation,” said Carlos Domingo, senior executive officer at Du. “We need a new breed of sensor friendly network to establish the smart city ecosystem. Thanks to Du, this capability now exists in the UAE Today we’ve shown how our network capabilities and digital know-how can deliver the smart city ecosystem Dubai needs. We will not stop in Dubai; our deployment will continue country-wide throughout the UAE.”

But the biggest recent LoRa news is that Orange has committed itself to a national French network rollout, following an investment in key LoRa player Actility. Orange has previously trialed a LoRa network in Grenoble, and has said that it opted for LoRa over Sigfox thanks to its more open ecosystem – although it’s worth clarifying here that Semtech still gets a royalty on every LoRa chip that’s made, and will continue to do so until it chooses not to or instead donates the IP to the non-profit LoRa Alliance itself.

It would be interesting to see if this LoRa vs CIoT ends up the same way as WiMAX vs LTE or not.

Embedded below is the 4G Americas whitepaper as well as a LoRa presentation from Semtech:

Further reading:

• Sigfox and LoRa march onwards as Weightless releases dev kit; the race to gain a foothold before the arrival of the LTE equivalents - Rethink Research
• The LoRa® Alliance Launches the LoRaWAN™ Certification Program
• Semtech LoRa Community Overview
• Consortium including Orange and Foxconn backs LoRa IoT startup Actility
• Harmonizing the industry on a narrowband IoT (NB-IoT) specification
• New LTE standard for Internet of Things gets push from 3GPP

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.