Showing posts with label White Papers and Reports. Show all posts
Showing posts with label White Papers and Reports. Show all posts

Wednesday, 18 November 2015

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:

Thursday, 15 October 2015

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.

Monday, 14 September 2015

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

Tuesday, 4 August 2015

The Importance of License Exempt Frequency Bands

Some of you may be aware that I am also a Technical Programme Manager with the UK Spectrum Policy Forum. Recently we published a whitepaper that we had commissioned to Plum consulting on "Future use of Licence Exempt Radio Spectrum". It is an interested read not only for spectrum experts but also for people trying to understand the complex world of spectrum.

The report is very well written. Here are a few extracts in purple:

Licence exempt frequency bands are those that can be used by certain applications without the need for prior authorisation or an individual right of use. This does not mean that they are not subject to regulation – use must still comply with pre-defined technical rules to minimise the risk of interference. Most licence exempt bands are harmonised throughout Europe and are shared with other services or applications, such as radars or industrial, scientific and medical (ISM) equipment. Wi-Fi and Bluetooth are probably the most familiar examples of mass-market licence exempt wireless applications, but the bands support many other consumer devices, such as cordless phones, doorbells, car key fobs, central heating controllers, baby monitors and intruder alarms. Looking to the future, licence exempt bands are likely to be a key enabler of wireless machine to machine (M2M) communication applications.

Key benefits of licence exempt bands include:
  • For end-users:
    • Greater convenience and flexibility by avoiding the need for lengthy runs of cable in home and work environments
    • Ability to connect mobile devices to a fixed broadband network, reducing dependence on the mobile network and potentially saving costs both for the service provider and the end-user
    • Enhanced convenience, safety and security, e.g. through installation of low cost wireless alarm systems or ability to unlock vehicles remotely rather than fumbling with keys
  • For equipment vendors and operators:
    • Facilitating market entry – there is no need to acquire a licence to deploy a service
    • Enabling niche applications or services to be addressed quickly and cheaply using existing technology and spectrum – this has been particularly effective in serving new machine to machine (M2M) applications in areas such as health, transport and home automation.
    • Providing certainty about spectrum access – there is no need to compete or pay for spectrum access (though the collective nature of spectrum use means quality of service cannot be guaranteed)
    • The ability to extend the reach of fixed communication networks, by providing wireless local area connectivity in homes, businesses and at public traffic hotspots.
The two most notable drawbacks are the inability to guarantee quality of service and the more limited geographic range that is typically available (reflecting the lower power limits that apply to these bands). Licence exempt wireless applications cannot claim protection from interference arising from other users or radio services. They operate in shared frequency bands and must not themselves cause harmful interference to other radio services.

From a regulator’s perspective, licence exempt bands can be more problematic than licensed bands in terms of refarming spectrum, since it is difficult to prevent the continued deployment of legacy equipment in the bands or to monitor effectively their utilisation. There is also generally no control over numbers and / or location of devices, which can make sharing difficult and limits the amount of spectrum that can be used in this way.

In Europe, regulation of licence exempt bands is primarily dealt with at an international level by European institutions. Most bands are fully harmonised, whereby free circulation of devices that comply with the relevant standards is effectively mandated throughout the EU. However some bands are subject to “soft” harmonisation, where the frequency limits and technical characteristics are harmonised but adoption of the band is left to national administrations to decide.

A key recommendation, which I think would be very interesting and useful would be: Promote further international harmonisation of licence exempt bands, in particular the recently identified 870 – 876 MHz and 915 – 921 MHz band that are likely to be critical for supporting future M2M demand growth in Europe.

Note that a similar sub-1GHz band has been recommended for 5G for M2M/IoT. The advantage for low frequencies is that the coverage area is very large, suitable for devices with low date rates. Depending on how the final 5G would be positioned, it may well use the license exempt bands, similar to the LAA/LTE-U kind of approach maybe.

The whitepaper is embedded below and is available to download from here:

Tuesday, 21 July 2015

TDD-FDD Joint Carrier Aggregation deployed

As per Analysis Mason, of the 413 commercial LTE networks that have been launched worldwide by the end of 2Q 2015, FD-LTE accounts for 348 (or 84%) of them, while TD-LTE accounts for only 55 (or 13%). Having said that, TD-LTE will be growing in market share, thanks to the unpaired spectrum that many operators secured during the auctions. This, combined with LTE-A Small Cells (as recently demoed by Nokia Networks) can help offload traffic from hotspots.

Light Reading had an interesting summary of TD-LTE rollouts and status that is further summarised below:
  • China Mobile has managed to sign up more than 200 million subscribers in just 19 months, making it the fastest-growing operator in the world today. It has now deployed 900,000 basestations in more than 300 cities. From next year, it is also planning to upgrade to TDD+ which combines carrier aggregation and MIMO to deliver download speeds of up to 5 Gbit/s and a fivefold improvement in spectrum efficiency. TDD+ will be commercially available next year and while it is not an industry standard executives say several elements have been accepted by 3GPP. 
  • SoftBank Japan has revealed plans to trial LTE-TDD Massive MIMO, a likely 5G technology as well as an important 4G enhancement, from the end of the year. Even though it was one of the world's first operators to go live with LTE-TDD, it has until now focused mainly on its LTE-FDD network. It has rolled out 70,000 FDD basestations, compared with 50,000 TDD units. But TDD is playing a sharply increasing role. The operator expects to add another 10,000 TDD basestations this year to deliver additional capacity to Japan's data-hungry consumers. By 2019 at least half of SoftBank's traffic to run over the TDD network.

According to the Analysis Mason article, Operators consider TD-LTE to be an attractive BWA (broadband wireless access) replacement for WiMAX because:

  • most WiMAX deployments use unpaired, TD spectrum in the 2.5GHz and3.5GHz bands, and these bands have since been designated by the 3GPP as being suitable for TD-LTE
  • TD-LTE is 'future-proof' – it has a reasonably long evolution roadmap and should remain a relevant and supported technology throughout the next decade
  • TD-LTE enables operators to reserve paired FD spectrum for mobile services, which mitigates against congestion in the spectrum from fixed–mobile substitution usage profiles.

For people who may be interested in looking further into migrating from WiMAX to TD-LTE, may want to read this case study here.

I have looked at the joint FDD-TDD CA earlier here. The following is from the 4G Americas whitepaper on Carrier Aggregation embedded here.

Previously, CA has been possible only between FDD and FDD spectrum or between TDD and TDD spectrum. 3GPP has finalized the work on TDD-FDD CA, which offers the possibility to aggregate FDD and TDD carriers jointly. The main target with introducing the support for TDD-FDD CA is to allow the network to boost the user throughput by aggregating both TDD and FDD toward the same UE. This will allow the network to boost the UE throughput independently from where the UE is in the cell (at least for DL CA).

TDD and FDD CA would also allow dividing the load more quickly between the TDD and FDD frequencies. In short, TDD-FDD CA extends CA to be applicable also in cases where an operator has spectrum allocation in both TDD and FDD bands. The typical benefits of CA – more flexible and efficient utilization of spectrum resources – are also made available for a combination of TDD and FDD spectrum resources. The Rel-12 TDD-FDD CA design supports either a TDD or FDD cell as the primary cell.

There are several different target scenarios in 3GPP for TDD-FDD CA, but there are two main scenarios that 3GPP aims to support. The first scenario assumes that the TDD-FDD CA is done from the same physical site that is typically a macro eNB. In the second scenario, the macro eNB provides either a TDD and FDD frequency, and the other frequency is provided from a Remote Radio Head (RRH) deployed at another physical location. The typical use case for the second scenario is that the macro eNB provides the FDD frequency and the TDD frequency from the RRH.

Nokia Networks were the first in the world with TDD-FDD CA demo, back in Feb 2014. In fact they also have a nice video here. Surprisingly there wasnt much news since then. Recently Ericsson announced the first commercial implementation of FDD/TDD carrier aggregation (CA) on Vodafone’s network in Portugal. Vodafone’s current trial in its Portuguese network uses 15 MHz of band 3 (FDD 1800) and 20 MHz of band 38 (TDD 2600). Qualcomm’s Snapdragon 810 SoC was used for measurement and testing.

3 Hong Kong is another operator that has revealed its plans to launch FDD-TDD LTE-Advanced in early 2016 after demonstrating the technology on its live network.

The operator used equipment supplied by Huawei to aggregate an FDD carrier in either of the 1800 MHz or 2.6 GHz bands with a TDD carrier in the 2.3 GHz band. 3 Hong Kong also used terminals equipped with Qualcomm's Snapdragon X12 LTE processor.

3 Hong Kong already offers FDD LTE-A using its 1800-MHz and 2.6-GHz spectrum, and is in the midst of deploying TD-LTE with a view to launching later this year.

The company said it expects devices that can support hybrid FDD-TDD LTE-A to be available early next year "and 3 Hong Kong is expected to launch the respective network around that time."

3 Hong Kong also revealed it plans to commercially launch tri-carrier LTE-A in the second half of 2016, and is working to aggregate no fewer than five carriers by refarming its 900-MHz and 2.1-GHz spectrum.

TDD-FDD CA is another tool in the network operators toolbox to help plan the network and make it better. Lets hope more operators take the opportunity to deploy one.

Sunday, 19 April 2015

3GPP Release-13 work started in earnest

The 3GPP news from some months back listed the main RAN features that have been approved for Release-13 and the work has already started on them. The following are the main features (links contain .zip files):

  • LTE in unlicensed spectrum (aka Licensed-Assisted Access) - RP-150055
  • Carrier Aggregation enhancements - RP-142286
  • LTE enhancements for Machine-Type Communications (MTC) - RP-141865
  • Enhancements for D2D - RP-142311
  • Study Item Elevation Beamforming / Full-Dimension MIMO - RP-141831
  • Study Item Enhanced multi-user transmission techniques - RP-142315
  • Study Item Indoor positioning - RP-141102
  • Study Item Single-cell Point-to-Multipoint (SC-PTM) - RP-142205

Another 3GPP presentation from late last year showed the system features that were being planned for Rel-13 as shown above.

I have also posted a few items earlier relating to Release13, as follows:

Ericsson has this week published a whitepaper on release 13, with a vision for 'Networked Society':
The vision of the Networked Society, where everything that benefits from being connected will be connected, places new requirements on connectivity. LTE is a key component in meeting these demands, and LTE release 13 is the next step in the LTE evolution.
Their whitepaper embedded below:

It should be pointed out that 5G work does not start until Release-15 as can be seen from my tweet

xoxoxo Added Later (26/04/2015) xoxoxo
I came across this presentation from Keysight (Agilent) where Moray Rumney has provided information in much more detail.

Saturday, 28 March 2015

Report on Spectrum Usage and Demand in the UK

Last week at work, we released a report titled "UK Spectrum Usage & Demand". The only time most people hear about spectrum is when there are some auctions going on. Often a small chunk of spectrum gets sold off for billion(s) of dollars/pounds and these surely make a headline. As I recently found out, 50% of spectrum in UK is shared and 25% is license exempt.

Anyway, this first edition of the report focuses on Public Mobile, Utilities, Business Radio and Space/Satellites. Space is becoming an important area of focus here as it is a significant contributor to the UK economy.

Anyway, the report is embedded below and is available to download from here:

Wednesday, 7 January 2015

Enhancing voice services using VoLTE

VoLTE has been a very popular topic on this blog. My overview of the LTE Voice Summit missed out narrowly from the Top 10 posts of 2014 but there were other posts related to VoLTE that made it.

In this magazine article, NTT Docomo not only talks about its own architecture and transition from 3G to 4G for voice and video, it provides some detailed insights from its own experience.

There is also discussion into technical details of the feature and examples of signalling for VoLTE registration and originating/terminating calls (control, session and user plane establishment), SMS, SRVCC, Video over LTE (ViLTE) and voice to video call switching.

The paper is embedded below and available from slideshare to download.

Related links:

Tuesday, 23 December 2014

M2M embedded UICC (eSIM) Architecture and Use Cases

Machine-to-Machine UICC, also known as M2M Form Factor (MFF) and is often referred to as embedded SIM (eSIM) is a necessity for the low data rate M2M devices that are generally small, single contained unit that is also sealed. The intention is that once this M2M device is deployed, then there is no need to remove the UICC from it. There may be a necessity to change the operator for some or the other reason. This gives rise to the need of multi-operator UICC (SIM) cards.

The GSMA has Embedded SIM specifications available for anyone interested in implementing this. There are various documents available on the GSMA page for those interested in this topic further.

While the complete article is embedded below, here is an extract of the basic working from the document:

A eUICC is a SIM card with a Remote Provisioning function, and is designed not to be removed or changed. It is able to store multiple communication profiles, one of which is enabled (recognized by the device and used for communication). The network of the MNO in the enabled profile is used for communication. Profiles other than the enabled profile are disabled (not recognized by the device). With conventional SIM cards, the ICCID is used as the unique key to identify the SIM card, but with eUICC, the ICCID is the key used to identify profiles, and a new ID is defined, called the eUICCID, which is used as the unique key for the eSIM

GSMA defines two main types of profile.
1) Provisioning Profile: This is the communication profile initially stored in the eUICC when it is shipped. It is a limited-application communication profile used only for downloading and switching Operational Profiles, described next.
2) Operational Profile: This is a communication profile for connecting to enterprise servers or the Internet. It can also perform the roles provided by a Provisioning profile

An eSIM does not perform profile switching as a simple IC card function, but rather switches profiles based on instructions from equipment called a Subscription Manager. A Subscription Manager is maintained and managed by an MNO. The overall eSIM architecture, centering on the Subscription Manager, is shown in Figure 3, using the example of switching profiles within the eUICC.

An eUICC must have at least one profile stored in it to enable OTA functionality, and one of the stored profiles must be enabled. The enabled profile uses the network of MNO A for communication. When the user switches profiles, a switch instruction is sent to the Subscription Manager. At that time, if the profile to switch to is not stored in the eUICC, the profile is first downloaded. When it receives a switch instruction, the eUICC performs a switch of the enabled profile as an internal process.

After the switch is completed, it uses the network of MNO B to send notification that the switch has completed to the Subscription Manager, completing the process. The same procedure is used to switch back to the original MNO A, or to some other MNO C.

Anyway, here is the complete paper:

Monday, 1 December 2014

Bringing Network Function Virtualization (NFV) to LTE

SDN and NFV have gained immense popularity recently. Not only are they considered important for reducing the Capex and Opex but are being touted as an important cog in the 4.5G/5G network. See here for instance.

I introduced NFV to the blog nearly a year back here. ETSI had just published their first specs around then. When I talked about SDN/NFV back in May, these ETSI standards were evolving into a significant reference documents. This is a reason 4G Americas recently published this whitepaper (embedded below), for the operators to start migrating to NFV architecture to reap long term benefits. The following is from the whitepaper:

The strategies and solutions explored in the 4G Americas report on NFV aim to address these issues and others by leveraging IT virtualization technology to consolidate many network equipment types onto industry standard high volume servers, networking and storage. NFV is about separating network functions from proprietary hardware and then consolidating and running those functions as virtualized applications on a commodity server. Broadly speaking, NFV will enable carriers to virtualize network functions and run them as software applications within their networks. NFV focuses on virtualizing network functions such as firewalls, Wide-Area Network (WAN) acceleration, network routers, border controllers (used in Voice over IP (VoIP) networks), Content Delivery Networks (CDNs) and other specialized network applications. NFV is applicable to a wide variety of networking functions in both fixed and mobile networks.
“NFV is making great progress throughout the world as operators work with their vendor partners to address the opportunities of increasing efficiency within their network infrastructure elements,” stated Chris Pearson, President of 4G Americas. “There is a great deal of collaborative innovation and cooperation between wireless carriers, IT vendors, networking companies and wireless infrastructure vendors making NFV for LTE possible.”
Global communication service providers, along with many leading vendors, are participating in the European Telecommunications Standards Institute’s (ETSI) Industry Specification Group for Network Functions Virtualization (NFV ISG) to address challenges such as:
  • An increasing variety of proprietary hardware appliances like routers, firewalls and switches
  • Space and power to accommodate these appliances
  • Capital investment challenges
  • Short lifespan
  • A long procure-design-integrate-deploy lifecycle
  • Increasing complexity and diversity of network traffic
  • Network capacity limitations
Three main benefits of NFV outlined in the 4G Americas paper include:
  • Improved capital efficiency: Provisioning capacity for all functions versus each individual function, providing more granular capacity, exploiting the larger economies of scale associated with Commercial Off-the-Shelf (COTS) hardware, centralizing Virtual Network Functions (VNFs) in data centers where latency requirements allow, and separately and dynamically scaling VNFs residing in the user (or data or forwarding) plane designed for execution in the cloud, control and user-plane functions as needed.
  • Operational efficiencies: Deploying VNFs as software using cloud management techniques which enables scalable automation at the click of an operator’s (or customer’s) mouse or in response to stimulus from network analytics. The ability to automate onboarding, provisioning and in-service activation of new virtualized network functions can yield significant savings. 
  • Service agility, innovation and differentiation: In deploying these new VNFs, time-to-market for new network services can be significantly reduced, increasing the operator’s ability to capture market share and develop market-differentiating services.
In particular, mobile operators can take advantage of NFV as new services are introduced. Evolved Packet Core (EPC), Voice over LTE (VoLTE), IP Multimedia System (IMS) and enhanced messaging services, among others, are examples of opportunities to use virtualized solutions. Some operators started deploying elements of NFV in 2013 with an expectation that many service areas could be mostly virtualized in the next decade.

The whitepaper as follows:

Tuesday, 11 November 2014

New Spectrum Usage Paradigms for 5G

Sometime back I wrote a post that talked about Dynamic Spectrum Access (DSA) techniques for Small Cells and WiFi to work together in a fair way. The Small Cells would be using the ISM bands and Wi-Fi AP's would also be contending for the same spectrum. For those who may not know, this is commonly referred to as LTE-U but the correct term that is being used in standards is LA-LTE, see here for details.

IEEE Comsoc has just published a whitepaper that details how the spectrum should be handled in 5G to make sure of efficient utilisation. The whitepaper covers the following:

Chapter 2 – Introduction, the traditional approach of repurposing spectrum and allocating it to Cellular Wireless systems is reaching its limits, at least below the 6GHz threshold. For this reason, novel approaches are required which are detailed in the sequel of this White Paper.

Chapter 3 - Spectrum Scarcity - an Alternate View provides a generic view on the spectrum scarcity issue and discusses key technologies which may help to alleviate the problem, including Dynamic Spectrum Management, Cognitive Radios, Cognitive Networks, Relaying, etc. 

Chapter 4 – mmWave Communications in 5G addresses a first key solution. While spectrum opportunities are running out at below 6 GHz, an abundance of spectrum is available in mmWave bands and the related technology is becoming mature. This chapter addresses in particular the heterogeneous approach in which legacy wireless systems are operated jointly with mmWave systems which allows to combine the advantages of both technologies. 

Chapter 5 – Dynamic Spectrum Access and Cognitive Radio: A Current Snapshot gives a detailed overview on state-of-the-art dynamic spectrum sharing technology and related standards activities. The approach is indeed complementary to the upper mmWave approach, the idea focuses on identifying unused spectrum in time, space and frequency. This technology is expected to substantially improve the usage efficiency of spectrum, in particular below the 6GHz range. 

Chapter 6 – Licensed Shared Access (LSA) enables coordinated sharing of spectrum for a given time period, a given geographic area and a given spectrum band under a license agreement. In contract to sporadic usage of spectrum on a secondary basis, the LSA approach will guarantee Quality-of-Service levels to both Incumbents and Spectrum Licensees. Also, a clear business model is available through a straightforward license transfer from relevant incumbents to licensees operating a Cellular Wireless network in the concerned frequency bands. 

Chapter 7 – Radio Environment Map details a technology which allows to gather the relevant (radio) context information which feed related decision making engines in the Network Infrastructure and/or Mobile Equipment. Indeed, tools for acquiring context information is critical for next generation Wireless Communication systems, since they are expected to be highly versatile and to constantly adapt. 

Chapter 8 – D2DWRAN: A 5G Network Proposal based on IEEE 802.22 and TVWS discusses the efficient exploitation of TV White Space spectrum bands building on the available IEEE 802.22 standard. TV White Spaces are indeed located in highly appealing spectrum bands below 1 GHz with propagation characteristics that are perfectly suited to the need of Wireless Communication systems. 

Chapter 9 – Conclusion presents some final thoughts. 

The paper is embedded as follows:

Thursday, 23 October 2014

Detailed whitepaper on Carrier Aggregation by 4G Americas

4G Americas has published a detailed whitepaper on Carrier Aggregation (CA). Its a very good detailed document for anyone wishing to study CA.

Two very important features that have come as part of CA enhancements were the multiple timing advance values that came as a part of Release-11 and TDD-FDD joint operation that came part of Release-12

While its good to see that up to 3 carriers CA is now possible as part of Rel-12 and as I mentioned in my last post, we need this to achieve the 'Real' 4G. We have to also remember at the same time that these CA makes the chipsets very complex and may affect the sensitivity of the RF receivers.

Anyway, here is the 4G Americas whitepaper.

LTE Carrier Aggregation Technology Development and Deployment Worldwide from Zahid Ghadialy

You can read more about the 4G Americas whitepaper in their press release here.

Saturday, 26 July 2014

Observed Time Difference Of Arrival (OTDOA) Positioning in LTE

Its been a while I wrote anything on Positioning. The network architecture for the positioning entities can be seen from my old blog post here
Qualcomm has recently released a whitepaper on the OTDOA (Observed Time Difference Of Arrival) positioning. Its quite a detailed paper with lots of technical insights.

There is also signalling and example of how reference signals are used for OTDOA calculation. Have a look at the whitepaper for detail, embedded below.

Tuesday, 18 February 2014

The Rise and Rise or '4G' - Update on Release-11 & Release-12 features

A recent GSMA report suggests that China will be a significant player in the field of 4G with upto 900 million 4G users by 2020. This is not surprising as the largest operator, China Mobile wants to desperately move its user base to 4G. For 3G it was stuck with TD-SCDMA or the TDD LCR option. This 3G technology is not as good as its FDD variant, commonly known as UMTS.

This trend of migrating to 4G is not unique to China. A recent report (embedded below) by 4G Americas predicts that by the end of 2018, HSPA/HSPA+ would be the most popular technology whereas LTE would be making an impact with 1.3 Billion connected devices. The main reason for HSPA being so dominant is due to the fact that HSPA devices are mature and are available now. LTE devices, even though available are still slightly expensive. At the same time, operators are taking time having a seamless 4G coverage throughout the region. My guess would be that the number of devices that are 4G ready would be much higher than 1.3 Billion.

It is interesting to see that the number of 'Non-Smartphones' remain constant but at the same time, their share is going down. It would be useful to breakdown the number of Smartphones into 'Phablets' and 'non-Phablets' category.

Anyway, the 4G Americas report from which the information above is extracted contains lots of interesting details about Release-11 and Release-12 HSPA+ and LTE. The only problem I found is that its too long for most people to go through completely.

The whitepaper contains the following information:

3GPP Rel-11 standards for HSPA+ and LTE-Advanced were frozen in December 2012 with the core network protocols stable in December 2012 and Radio Access Network (RAN) protocols stable in March 2013. Key features detailed in the paper for Rel-11 include:
  • 8-carrier downlink operation (HSDPA)
  • Downlink (DL) 4-branch Multiple Input Multiple Output (MIMO) antennas
  • DL Multi-Flow Transmission
  • Uplink (UL) dual antenna beamforming (both closed and open loop transmit diversity)
  • UL MIMO with 64 Quadrature Amplitude Modulation (64-QAM)
  • Several CELL_FACH (Forward Access Channel) state enhancements (for smartphone type traffic) and non-contiguous HSDPA Carrier Aggregation (CA)
  • Carrier Aggregation (CA)
  • Multimedia Broadcast Multicast Services (MBMS) and Self Organizing Networks (SON)
  • Introduction to the Coordinated Multi-Point (CoMP) feature for enabling coordinated scheduling and/or beamforming
  • Enhanced Physical Control Channel (EPDCCH)
  • Further enhanced Inter-Cell Interference Coordination (FeICIC) for devices with interference cancellation
Finally, Rel-11 introduces several network and service related enhancements (most of which apply to both HSPA and LTE):
  • Machine Type Communications (MTC)
  • IP Multimedia Systems (IMS)
  • Wi-Fi integration
  • Home NodeB (HNB) and Home e-NodeB (HeNB)
3GPP started work on Rel-12 in December 2012 and an 18-month timeframe for completion was planned. The work continues into 2014 and areas that are still incomplete are carefully noted in the report.  Work will be ratified by June 2014 with the exception of RAN protocols which will be finalized by September 2014. Key features detailed in the paper for Rel-12 include:
  • Universal Mobile Telecommunication System (UMTS) Heterogeneous Networks (HetNet)
  • Scalable UMTS Frequency Division Duplex (FDD) bandwidth
  • Enhanced Uplink (EUL) enhancements
  • Emergency warning for Universal Terrestrial Radio Access Network (UTRAN)
  • HNB mobility
  • HNB positioning for Universal Terrestrial Radio Access (UTRA)
  • Machine Type Communications (MTC)
  • Dedicated Channel (DCH) enhancements
  • Active Antenna Systems (AAS)
  • Downlink enhancements for MIMO antenna systems
  • Small cell and femtocell enhancements
  • Machine Type Communication (MTC)
  • Proximity Service (ProSe)
  • User Equipment (UE)
  • Self-Optimizing Networks (SON)
  • Heterogeneous Network (HetNet) mobility
  • Multimedia Broadcast/Multicast Services (MBMS)
  • Local Internet Protocol Access/Selected Internet Protocol Traffic Offload (LIPA/SIPTO)
  • Enhanced International Mobile Telecommunications Advanced (eIMTA) and Frequency Division Duplex-Time Division Duplex Carrier Aggregation (FDD-TDD CA)
Work in Rel-12 also included features for network and services enhancements for MTC, public safety and Wi-Fi integration, system capacity and stability, Web Real-Time Communication (WebRTC), further network energy savings, multimedia and Policy and Charging Control (PCC) framework.

Friday, 13 December 2013

Advancements in Congestion control technology for M2M

NTT Docomo recently published a new article (embedded below) on congestion control approaches for M2M. In their own words:

Since 3GPP Release 10 (Rel. 10) in 2010, there has been active study of technical specifications to develop M2M communications further, and NTT DOCOMO has been contributing proactively to creating these technical specifications. In this article, we describe two of the most significant functions standardized between 3GPP Rel. 10 and Rel. 11: the M2M Core network communications infrastructure, which enables M2M service operators to introduce solutions more easily, and congestion handling technologies, which improve reliability on networks accommodating a large number of terminals.

Complete article as follows:

Other related posts:

Monday, 4 November 2013

Key challenges with automatic Wi-Fi / Cellular handover

Recently in a conference I mentioned that the 3GPP standards are working on standards that will allow automatic and seamless handovers between Cellular and Wi-Fi. At the same time operators may want to have a control where they can automatically switch on a users Wi-Fi radio (if switched off) and offload to Wi-Fi whenever possible. It upset quite a few people who were reasoning against the problems this could cause and the issues that need to be solved.

I have been meaning to list the possible issues which could be present in this scenario of automatically handing over between Wi-Fi and cellular, luckily I found that they have been listed very well in the recent 4G Americas whitepaper. The whitepaper is embedded below but here are the issues I had been wanting to discuss:

In particular, many of the challenges facing Wi-Fi/Cellular integration have to do with realizing a complete intelligent network selection solution that allows operators to steer traffic in a manner that maximizes user experience and addresses some of the challenges at the boundaries between RATs (2G, 3G, LTE and Wi-Fi).
Figure 1 (see above) below illustrates four of the key challenges at the Wi-Fi/Cellular boundary.
1) Premature Wi-Fi Selection: As devices with Wi-Fi enabled move into Wi-Fi coverage, they reselect to Wi-Fi without comparative evaluation of existing cellular and incoming Wi-Fi capabilities. This can result in degradation of end user experience due to premature reselection to Wi-Fi. Real time throughput based traffic steering can be used to mitigate this.
2) Unhealthy choices: In a mixed wireless network of LTE, HSPA and Wi-Fi, reselection may occur to a strong Wi-Fi network, which is under heavy load. The resulting ‘unhealthy’ choice results in a degradation of end user experience as performance on the cell edge of a lightly loaded cellular network may be superior to performance close to a heavily loaded Wi-Fi AP. Real time load based traffic steering can be used to mitigate this.
3) Lower capabilities: In some cases, reselection to a strong Wi-Fi AP may result in reduced performance (e.g. if the Wi-Fi AP is served by lower bandwidth in the backhaul than the cellular base station presently serving the device). Evaluation of criteria beyond wireless capabilities prior to access selection can be used to mitigate this.
4) Ping-Pong: This is an example of reduced end user experience due to ping-ponging between Wi-Fi and cellular accesses. This could be a result of premature Wi-Fi selection and mobility in a cellular environment with signal strengths very similar in both access types. Hysteresis concepts used in access selection similar to cellular IRAT, applied between Wi-Fi and cellular accesses can be used to mitigate this.
Here is the paper:

Tuesday, 15 October 2013

What is Network Function Virtualisation (NFV)?

Software Defined Networking (SDN) and Network Function Virtualization (NFV) are the two recent buzzwords taking the telecoms market by storm. Every network vendor now has some kind of strategy to use this NFV and SDN to help operators save money. So what exactly is NFV? I found a good simple video by Spirent that explains this well. Here it is:

To add a description to this, I would borrow an explanation and a very good example from Wendy Zajack, Director Product Communications, Alcatel-Lucent in ALU blog:

Let’s take this virtualization concept to a network environment. For me cloud means I can get my stuff where ever I am and on any device –  meaning I can pull out my smart phone, my iPad, my computer – and show my mom the  latest pictures of  her grand kids.  I am not limited to only having one type of photo album I put my photos in – and only that. I can also show her both photos and videos together – and am not just limited to showing her the kids in one format and on one device.
Today in a telecom network is a lot of equipment that can only do one thing.  These machines are focused on what they are do and they do it really well – this is why telecom providers are considered so ‘trusted.’ Back in the days of landline phones even when the power was out you could always make a call.  These machines run alone with dedicated resources.  These machines are made by various different vendors and speak various languages or ‘protocols’ to exchange information with each other when necessary. Some don’t even talk at all – they are just set-up and then left to run.  So, every day your operator is running a mini United Nations and corralling that to get you to access all of your stuff.  But it is a United Nations with a fixed number of seats, and with only a specific nation allowed to occupy a specific seat, with the seat left unused if there was a no-show. That is a lot of underutilized equipment that is tough and expensive to manage.  It also has a shelf life of 15 years… while your average store-bought computer is doubling in speed every 18 months.
Virtualizing the network means the ability to run a variety of applications (or functions) on a standard piece of computing equipment, rather than on dedicated, specialized processors and equipment, to drive lower costs (more value), more re-use of the equipment between applications (more sharing), and a greater ability to change what is using the equipment to meet the changing user needs (more responsiveness).  This has already started in enterprises as a way to control IT costs and improve the performance and of course way greener.
To give this a sports analogy – imagine if in American football instead of having specialists in all the different positions (QB, LB, RB, etc), you had a bunch of generalists who could play any position – you might only need a 22 or 33 man squad (2 or 3 players for every position) rather than the normal squad of  53.   The management of your team would be much simpler as ‘one player fits all’ positions.   It is easy to see how this would benefit a service provider – simplifying the procurement and management of the network elements (team) and giving them the ability to do more, with less.

Dimitris Mavrakis from Informa wrote an excellent summary from the IIR SDN and NFV conference in Informa blog here. Its worth reading his article but I want to highlight one section that shows how the operators think deployment would be done:

The speaker from BT provided a good roadmap for implementing SDN and NFV:
  1. Start with a small part of the network, which may not be critical for the operation of the whole. Perhaps introduce incremental capacity upgrades or improvements in specific and isolated parts of the network.
  2. Integrate with existing OSS/BSS and other parts of the network.
  3. Plan a larger-scale rollout so that it fits with the longer-term network strategy.
Deutsche Telecom is now considered to be deploying in the first phase, with a small trial in Hrvatski Telecom, its Croatian subsidiary, called Project Terrastream. BT, Telefonica, NTT Communications and other operators are at a similar stage, although DT is considered the first to deploy SDN and NFV for commercial network services beyond the data center.
Stage 2 in the roadmap is a far more complicated task. Integrating with existing components that may perform the same function but are not virtualized requires east-west APIs that are not clearly defined, especially when a network is multivendor. This is a very active point of discussion, but it remains to be seen whether Tier-1 vendors will be willing to openly integrate with their peers and even smaller, specialist vendors. OSS/BSS is also a major challenge, where multivendor networks are controlled by multiple systems and introducing a new service may require risking several parameters in many of these OSS/BSS consoles. This is another area that is not likely to change rapidly but rather in small, incremental steps.
The final stage is perhaps the biggest barrier due to the financial commitment and resources required. Long-term strategy may translate to five or even 10 years ahead – when networks are fully virtualized – and the economic environment may not allow such bold investments. Moreover, it is not clear if SDN and NFV guarantee new services and revenues outside the data center or operator cloud. If they do not, both technologies – and similar IT concepts – are likely to be deployed incrementally and replace equipment that reaches end-of-life. Cost savings in the network currently do not justify forklift upgrades or the replacement of adequately functional network components.
There is also a growing realization that bare-metal platforms (i.e., the proprietary hardware-based platforms that power today’s networks) are here to stay for several years. This hardware has been customized and adapted for use in telecom networks, allowing high performance for radio, core, transport, fixed and optical networks. Replacing these high-capacity components with virtualized ones is likely to affect performance significantly and operators are certainly not willing to take the risk of disrupting the operation of their network.
A major theme at the conference was that proprietary platforms (particularly ATCA) will be replaced by common off-the-shelf (COTS) hardware. ATCA is a hardware platform designed specifically for telecoms, but several vendors have adapted the platform to their own cause, creating fragmentation, incompatibility and vendor lock-in. Although ATCA is in theory telecoms-specific COTS, proprietary extensions have forced operators to turn to COTS, which is now driven by IT vendors, including Intel, HP, IBM, Dell and others.

ETSI has just published first specifications on NFV. Their press release here says:

ETSI has published the first five specifications on Network Functions Virtualisation (NFV). This is a major milestone towards the use of NFV to simplify the roll-out of new network services, reduce deployment and operational costs and encourage innovation.
These documents clearly identify an agreed framework and terminology for NFV which will help the industry to channel its efforts towards fully interoperable NFV solutions. This in turn will make it easier for network operators and NFV solutions providers to work together and will facilitate global economies of scale.
The IT and Network industries are collaborating in ETSI's Industry Specification Group for Network Functions Virtualisation (NFV ISG) to achieve a consistent approach and common architecture for the hardware and software infrastructure needed to support virtualised network functions. Early NFV deployments are already underway and are expected to accelerate during 2014-15. These new specifications have been produced in less than 10 months to satisfy the high industry demand – NFV ISG only began work in January 2013.
NFV ISG was initiated by the world's leading telecoms network operators. The work has attracted broad industry support and participation has risen rapidly to over 150 companies of all sizes from all over the world, including network operators, telecommunication equipment vendors, IT vendors and technology providers. Like all ETSI standards, these NFV specifications have been agreed by a consensus of all those involved.
The five published documents (which are publicly available via include four ETSI Group Specifications (GSs) designed to align understanding about NFV across the industry. They cover NFV use cases, requirements, the architectural framework, and terminology. The fifth GS defines a framework for co-ordinating and promoting public demonstrations of Proof of Concept (PoC) platforms illustrating key aspects of NFV. Its objective is to encourage the development of an open ecosystem by integrating components from different players.
Work is continuing in NFV ISG to develop further guidance to industry, and more detailed specifications are scheduled for 2014. In addition, to avoid the duplication of effort and to minimise fragmentation amongst multiple standards development organisations, NFV ISG is undertaking a gap analysis to identify what additional work needs to be done, and which bodies are best placed to do it.
The ETSI specifications are available at:

The first document that shows various use cases is embedded below: