Summary of Cambridge Wireless Event on Small Cells, 3rd Oct. 2012

We had another successful Small Cells SIG Event (jointly powered by the Radio Technology SIG) in Cambridge Wireless on the theme “Radio Challenges and Opportunities for Large Scale Small Cell Deployments”. I will be looking at the presentations in detail in separate blog posts as there are interesting bits and pieces from each of them that can easily be overlooked. Here is a high level summary of this event.

We had over a hundred delegates in this event and as one of the speakers admitted privately, they were expecting to see around a dozen people and were a bit overwhelmed by the number and caliber of the people. The delegates included small cell vendors, chipset vendors, test & measurement vendors, operators, industry analysts, regulators, etc. It was a lovely day to be in Cambridge with the sun shining the whole of morning and the afternoon to show us the best of the Downing college.

The event was kicked off by Prof. Simon Saunders, formerly the founding chairman of Small Cell Forum who talked about the long journey the small cells (or Femtocells as they were then known) have gone through, the benefits and the road ahead.

This was followed by a talk from Julius Robson of CBNL, who was also representing NGMN. The focus of the talk was on backhaul.

Nick Johnson, CTO of ip.access was the next speaker who started his presentation with humorous note. His presentation was titled "Building the World’s Largest Residential Small-Cell network" but as he said he was very tempted to change the title to “How to Screw Up the World’s Largest Residential Small Cell Deployment”. His talk had lots of real life examples on where and how things can go wrong and how to make sure they dont. If they do, what lessons should be learnt. Some of these problems have been faced by me too in various test scenarios. It was a very interesting talk.

After the break we heard a presentation from Steve Brown of Telefonica O2 UK. The talk was a bit familiar for me (and my blog readers) as I have already blogged on similar information in the past. It was though new information for the audience and could see that they were enjoying this information. A lot of questions were asked after the presentation and also in the panel discussion at the end. There is some interesting new information that I will blog later on.

The final talk was by Iris Barcia of Keima who talked about "Small Cell Network Design".

Finally we had a panel discussion with lots of interesting questions. Once the discussions finished there were people discussing and debating issues among themselves for a long time. I am looking forward to the next event in January in London on the topic "Lets get real!" where we are hoping to be able to hear from some more operators/vendors on the deployment and rollout issues. More details available on the Cambridge Wireless page here.

'Hypervoice': The Future of voice - via @martingeddes

Interesting thought provoking presentation!

3D-Beamforming and 3D-MIMO

When I did the summary from Rel-12 workshop, one of the feature proposed by many companies was the feature on 3D MIMO/Beamforming. Here is a quick introduction from different presentations.

A presentation by China mobile lists the motivations and Challenges is embedded below:

LTE Evolution — Rel-12 and Beyond from Zahid Ghadialy

#LTEAsia 2012 Highlights - via Alan Quayle

A summary of LTE Asia 2012, slides and highlights via Alan Quayle blog.



Some of the interesting findings from the conference include:

• TD-LTE is gaining momentum, and its beyond WiMAX operators and China mobile, many APAC operators are considering it for unpaired spectrum and to efficiently meet the asymmetric capacity requirements of mobile broadband which is mainly download
• Software defined radio and self-organizing networks are proving critical to manage operational costs
• Single RAN is proving the best way to manage network performance
• Signaling is in a mess - what is the good of standards when it creates such a mess?
• IMS gaps continue - what is the good of standards when it doesn't meet basic migration needs?
• The SS7 guys have reinvented themselves as the Diameter guys
• Business model innovation - LTE is not just for mobile devices, LTE is for quad play and an interesting array of business applications
• The 3G network of many operators is congested - forcing the move to LTE
• CSFB (Circuit Switched Fall Back) works
• VoLTE testing / roaming / network issues remain - given voice remains by revenue the core service, our industry should be ashamed we're having so many problems with VoLTE
• A belief on OTT partnering, but not quantification on the OTT's willingness to pay for QoS (Quality of Service)
• Many operators have a question mark on the use of WiFi off-load - its not a technology issue rather one of economics and customer experience, LTE-A and small cells in hotspots appears to be the focus.

Briefly reviewing the slides shown below:

• LTE Data Points
• 96 Commercial LTE deployments mainly in the 1.8 and 2.8GHz bands
• APAC has 40% of LTE subscribers, likely to be the high growth region
• Drivers for LTE: Throughput, efficiency and low latency
• TD-LTE: 12 commercial deployments, 24 contracts and 53 Trials
• Streaming video dominates traffic on handheld devices, with YouTube being the top traffic generator at 27% of peak traffic
• South Korea Data Explosion
• South Korea has seen OTT explode, Kakao Talk 51 mins of usage per day
• 20 times smartphone growth in 2 years (28M in June 2012, 53% penetration)
• 60 times mobile data growth to 37TB per month in 2 years, 32% is from LTE devices
• LTE subs use 2.9GB per month compared to 3G sub on average use 1.2GB
• LTE subs reached 10M, 141% monthly growth
• Customer drive for LTE is speed (37%) and latest device (31%)
• Challenge Jan 2010 and Jan 2012 ARPU fallen from $48-$35 while data use risen from 180MB to 992MB
• Focus beyond voice, messaging and data into VAS: virtual goods (Korean thing), ICT (Information and Communication Technology) and cloud services / solutions (focus on enterprise)
• HK CSL Migration to LTE
• 3G is congested, LTE is not
• Key is LTE devices available, unlike the early 3G days
• Migrating customers away from unlimited plans to family and shared plans that deliver value
• LTE sub uses 2-5 times the data of 3G subs
• CSFB works
• Average speed seen is 20 Mbps
• Using Software Defined Radio, Single vendor RAN, Self-Organizing Networks
• Migration to LTE-A, small cells and WiFi where appropriate
• Starhub's migration to LTE (they launched LTE at the event)
• 50% of voice traffic is still on 2G
• Using AMR to re-farm 2G spectrum to LTE
• Site access is critical - drive to software defined radio to avoid site visits
• NTT DoCoMo's VoLTE Evolution
• 70% devices in portfolio are now LTE
• All smartphones support CSFB
• Drive to VoLTE is simply to switch off 3G voice (2G already off)
• BUT IMS has missing functionality / standards - migration from 3G to VoLTE is not easy - example of failing in standards on basic issues
• Yes: Example of innovative converged 4G operator in an developing market that uses web principles for service delivery
• Role of Mobile Identity in BYOD (Bring Your Own Device)
• BYOD is as significant a trend if APAC as any other market
• Provides a nice review of the approaches in managing BYOD
• LTE Quad-Play in Emerging Markets: TD-LTE case study
• Smartphone growth implications: Review of the signaling problem and mitigation strategies across 3G and LTE.  Highlights challenge current standards process 

Read the complete post here.

LTE: What is a Tracking Area

Even though I have known tracking area for a long time, the other day I struggled to explain exactly what it is. I found a good explanation in this new book 'An Introduction to LTE: LTE, LTE-Advanced, SAE and 4G Mobile Communications By Christopher Cox'. An extract from the book and Google embed is as follows:

The EPC is divided into three different types of geographical area, which are illustrated in Figure 2.6. (see Embed below).

An MME pool area is an area through which the mobile can move without a change of serving MME. Every pool area is controlled by one or more MMEs, while every base station is connected to all the MMEs in a pool area by means of the S1-MME interface. Pool areas can also overlap. Typically, a network operator might configure a pool area to cover a large region of the network such as a major city and might add MMEs to the pool as the signalling load in that city increases.

Similarly, an S-GW service area is an area served by one or more serving gateways, through which the mobile can move without a change of serving gateway. Every base station is connected to all the serving gateways in a service area by means of the S1-U interface. S-GW service areas do not necessarily correspond to MME pool areas.

MME pool areas and S-GW service areas are both made from smaller, non-overlapping units known as tracking areas (TAs). These are used to track the locations of mobiles that are on standby and are similar to the location and routing areas from UMTS and GSM.

M2M-Related Standardization Bodies

Related post:

• Standardisation on M2M at ETSI M2M platform

LTE-Advanced: An Operator Perspective

LTE, M2M Device Addressing and IMSI

I was made aware of the following statement on the Verizon wireless brochure:

LTE’s inherent support for IPV6 addressing and IMSI-based telephone number identifiers makes mass deployments over LTE more easily achievable. The deployment of large numbers of mobile devices (think tens of thousands) becomes much more feasible because of LTE’s use of 15-digit IMSI telephone number identifiers for large-scale deployments, such as M2M or embedded wireless applications. 3G network technologies were limited by their use of 10-digit telephone number identifiers, which made large-scale deployments more difficult. With LTE, mass deployment of wireless services and applications, such as VoIP, smart metering, vending, and telematics, is now practical.

Now we know about the much touted 50 Billion connections by 2025 of which the majority would be M2M devices. So how are we going to handle the issue of addressing these many devices.

In the earlier presentation here, there was a mention of the direction for the solution as below:

The IMSI structure is as shown above. So depending on how it is used this can help alleviate the number shortage problem. 3GPP TR 23.888 gives the following information:

5.13      Key Issue - MTC Identifiers

5.13.1    Use Case Description

The amount of MTC Devices is expected to become 2 orders of magnitude higher than the amount of devices for human to human communication scenarios. This has to be taken into account for IMSI, IMEI and MSISDN. Regulatory bodies indicate shortages of IMSIs and MSISDNs.

The MTC Feature PS Only in TS 22.368 [2] includes a requirement that PS Only subscriptions shall be possible without an MSISDN. In principle an MSISDN is not used in any of the PS based signalling procedures. However, it will have to be assured that all PS procedures indeed work and subscriptions can be uniquely identified without providing an MSISDN. Furthermore, TS 22.368 [2] specifies that remote MTC Device configuration shall be supported for PS only subscriptions without an MSDISDN assigned. Current remote MTC Device configuration solutions (i.e. Device Management and Over-the-Air configuration) are based on SMS, which assumes the use of MSISDNs. So a solution to support remote MTC Device configuration that does not require the use of MSISDNs is needed.

The identifiers can be categorised into:

-     Internal Identifiers: used within the 3GPP system to identify a UE using a subscription (or the subscription itself e.g. when the UE is not registered).

-     External Identifiers: used from outside the 3GPP system (e.g. at the MTCsp interface), to refer to a UE using a subscription (or the subscription itself e.g. when the UE is not registered).

5.13.2    Required Functionality

-     It shall be possible to uniquely identify the ME.

NOTE 1:   This requirement relates to the ME which is generally identified by the IMEI.

-     It shall be possible to uniquely identify the UE using a subscription or the subscription itself.

NOTE 2:   The two requirements above also apply to human-to-human communications. However, for Machine-Type Communication identifiers will have to be able to cater for a number of identifiers up to two orders of magnitude higher than for human-to-human communications.

-     It shall be possible to use the following identifiers:

1.       IMSI, for internal usage within the 3GPP operator domain, and either

2.       E.164 MSISDN, for usage outside the 3GPP operator domain, or

3.       Unique identifier (e.g. FQDN), other than E.164 MSISDN, for usage outside the 3GPP operator domain.

NOTE 3: Use of IMSI outside the 3GPP operator domain is an operator option (i.e. not subject to standardization)

-     If no (unique or common) MSISDN is assigned to a PS only subscription, the Internal Identifier (IMSI) shall be used as charging identifier.

-     It shall be possible to associate one or more External Identifiers to the same Internal Identifier (e.g. several MSISDNs associated with the same IMSI).

-     Globally unique External Identifiers shall be supported for identifying UEs used for MTC that must be globally reachable (i.e. irrespective of which mobile operator owns the subscription)

-     Operator specific External Identifiers (e.g. based on a private numbering plan) may be supported for identifying UEs used for MTC that have to be reachable only from the operator domain to which they are subscribed.

-     The Internal Identifier shall be globally unique.

-     Remote MTC Device configuration shall still be supported for subscriptions without an MSISDN.

NOTE 4:   Current remote MTC Device configuration solutions (i.e. Device Management and Over-the-Air configuration) are based on SMS, which assumes the use of MSISDNs.

Any more information on this subject, more than welcome.

Ovum: Global LTE Pricing Strategies

Here is another interesting presentation from the LTE World Summit:

Steven hartley ovum-thurs_zone-2_masterclass-2_thurs from ceobroadband

Other related posts:

• Right Pricing LTE ... and Mobile Broadband in general
• Right Pricing Mobile Broadband

Cellular-Wi-Fi Integration - technology and standardization roadmap

Interdigital: Cellular-Wi-Fi Integration from Zahid Ghadialy