Showing posts with label (e)MBMS. Show all posts
Showing posts with label (e)MBMS. Show all posts

Tuesday, 5 December 2017

Summary of 3GPP Release-14 Work Items

With all focus on 5G (Release-15), looks like Rel-14 has been feeling a bit neglected. There are some important updates though as it lays foundation for other services.

3GPP used to maintain Release Descriptions here for all different releases but have stopped doing that since 2014. For Release-14, a new document "3GPP TR 21.914: Release 14 Description; Summary of Rel-14 Work Items" is now available here.

An executive summary from the document:

Release 14 focusses on the following items:
  • Improving the Mission Critical aspects, in particular with the introduction of Video and Data services
  • Introducing the Vehicle-to-Everything (V2X) aspects, in particular the Vehicle-to-Vehicle (V2)
  • Improving the Cellular Internet of Things (CIoT) aspects, with 2G, 3G and 4G support of Machine-Type of Communications (MTC)
  • Improving the radio interface, in particular by enhancing the aspects related to coordination with WLAN and unlicensed spectrum
  • A set of uncorrelated improvements, e.g. on Voice over LTE (VoLTE), IMS, Location reporting.

The continuation of this document provides an exhaustive view of all the items specified by 3GPP in Release 14.

I have blogged about the Mission Critical Communications here. 3GPP has also done a webinar on this topic which can be viewed here. I like this slide below that summarizes features in different releases.

Then there are quite a few new features and enhancements for V2X. I have blogged about sidelink and its proposed extensions here.

From the document:

The Work Item on “Architecture enhancements for LTE support of V2X services (V2XARC)”, driven by SA WG2, specifies the V2X architectures, functional entities involved for V2X communication, interfaces, provisioned parameters and procedures in TS 23.285.
Figure above depicts an overall architecture for V2X communication. V2X Control Function is the logical function defined for network related actions required for V2X and performs authorization and provisioning of necessary parameters for V2X communication to the UE via V3 interface.

A UE can send V2X messages over PC5 interface by using network scheduled operation mode (i.e. centralized scheduling) and UE autonomous resources selection mode (i.e. distributed scheduling) when the UE is "served by E-UTRAN" while a UE can send V2X messages over PC5 interface only by using UE autonomous resources selection mode when the UE is "not served by E-UTRAN". 

Both IP based and non-IP based V2X messages over PC5 are supported. For IP based V2X messages over PC5, only IPv6 is used. PPPP (ProSe Per-Packet Priority) reflecting priority and latency for V2X message is applied to schedule the transmission of V2X message over PC5.

A UE can send V2X messages over LTE-Uu interface destined to a locally relevant V2X Application Server, and the V2X Application Server delivers the V2X messages to the UE(s) in a target area using unicast delivery and/or MBMS (Multimedia Broadcast/Multicast Service) delivery.

Both IP based and non-IP based V2X messages are supported for V2X communication over LTE-Uu. In order to transmit non-IP based V2X messages over LTE-Uu, the UE encapsulates the V2X messages in IP packets.

For latency improvements for MBMS, localized MBMS can be considered for localized routing of V2X messages destined to UEs.

For V2X communication over LTE-Uu interface, the V2X messages can be delivered via Non-GBR bearer (i.e. an IP transmission path with no reserved bitrate resources) as well as GBR bearer (i.e. an IP transmission path with reserved (guaranteed) bitrate resources). In order to meet the latency requirement for V2X message delivery, the following standardized QCI (QoS Class Identifier) values defined in TS 23.203 can be used:
  • QCI 3 (GBR bearer) and QCI 79 (Non-GBR bearer) can be used for the unicast delivery of V2X messages.
  • QCI 75 (GBR bearer) is only used for the delivery of V2X messages over MBMS bearers. 

There are updates to cellular IoT (CIot) which I have blogged about here.

There are some other interesting topic that are enhanced as part of Release14. Here are some of them:
  • S8 Home Routing Architecture for VoLTE
    • Robust Call Setup for VoLTE subscriber in LTE
    • Enhancements to Domain Selection between VoLTE and CDMA CS
    • MBMS improvements
    • eMBMS enhancements for LTE
    • IMS related items
    • Evolution to and Interworking with eCall in IMS
    • Password-based service activation for IMS Multimedia Telephony service
    • Multimedia Priority Service Modifications
    • Enhancements to Multi-stream Multiparty Conferencing Media Handling
    • Enhancement for TV service
    • Improved Streaming QoE Reporting in 3GPP (IQoE)
    • Quality of Experience (QoE) Measurement Collection for streaming services in UTRAN
    • Development of super-wideband and fullband P.835
    • Enhancements to User Location Reporting Support
    • Enhancing Location Capabilities for Indoor and Outdoor Emergency Communications
    • Further Indoor Positioning Enhancements for UTRA and LTE
    • Improvements of awareness of user location change
    • Terminating Access Domain Selection (T-ADS) supporting WLAN Access
    • Enhanced LTE-WLAN Aggregation (LWA)
    • Enhanced LTE WLAN Radio Level Integration with IPsec Tunnel (eLWIP)
    • Positioning Enhancements for GERAN
    • New GPRS algorithms for EASE
    • RRC optimization for UMTS
    • Multi-Carrier Enhancements for UMTS
    • DTX/DRX enhancements in CELL_FACH
    • LTE radio improvements
    • Enhancements on Full-Dimension (FD) MIMO for LTE
    • Downlink Multiuser Superposition Transmission for LTE
    • Performance enhancements for high speed scenario in LTE
    • Control and User Plane Separation (CUPS) of EPC nodes
    • Paging Policy Enhancements and Procedure
    • Shared Subscription Data Update
    • Service Domain Centralization
    • Control of Applications when Third party Servers encounter difficulties
    • PS Data Off Services
    • Enhancement to Flexible Mobile Service Steering 
    • Sponsored data connectivity improvements
    • Group based enhancements in the network capability exposure functions
    • Improved operator control using new UE configuration parameters
    • Charging and OAM stand alone improvements
    • Rel-14 Charging
    • ...

    Further Reading:

    Tuesday, 27 June 2017

    Mission Critical Services update from 3GPP - June 2017

    3GPP has published an overview of what has been achieved so far in the Mission Critical and also provides an outlook of what can be expected in the near future. A more detailed paper summarizing the use cases and functional aspects of Rel-13, Rel-14 and upcoming Rel-15 will be published later this year.

    Mission Critical Services – Detailed List of Rel-13, Rel-14 and Rel-15 Functionalities

    Rel-13 MCPTT (completed 2016)
    • User authentication and service authorization
    • Configuration
    • Affiliation and de-affiliation
    • Group calls on-network and off-network (within one system or multiple systems, pre-arranged or chat model, late entry, broadcast group calls, emergency group calls, imminent peril group calls, emergency alerts)
    • Private calls on-network and off-network (automatic or manual commencement modes, emergency private calls)
    • MCPTT security
    • Encryption (media and control signalling)
    • Simultaneous sessions for call
    • Dynamic group management (group regrouping)
    • Floor control in on-network (within one system or across systems) and in off-network
    • Pre-established sessions
    • Resource management (unicast, multicast, modification, shared priority)
    • Multicast/Unicast bearer control, MBMS (Multimedia Broadcast/Multicast Service) bearers
    • Location configuration, reporting and triggering
    • Use of UE-to-network relays
    Rel-14 MC Services (completed 2017)
    MC Services Common Functionalities:
    • User authentication and service authorization
    • Service configuration
    • Affiliation and de-affiliation
    • Extended Location Features
    • (Dynamic) Group Management
    • Identity management
    • MC Security framework
    • Encryption (media and control signalling)
    MCPTT Enhancements:
    • First-to-answer call setup (with and without floor control)
    • Floor control for audio cut-in enabled group
    • Updating the selected MC Service user profile for an MC Service
    • Ambient listening call
    • MCPTT private call-back request
    • Remote change of selected group
    MCVideo, Common Functions plus:
    • Group Call (including emergency group calls, imminent peril group calls, emergency alerts)
    • Private Call (off-network)
    • Transmission Control
    MCData, Common Functions plus:
    • Short Data Service (SDS)
    • File Distribution (FD) (on-network)
    • Transmission and Reception Control
    • Handling of Disposition Notifications
    • Communication Release
    Rel-15 MC Services (in progress)

    MC Services Common Functionalities Enhancements:
    • Enhanced MCPTT group call setup procedure with MBMS bearer
    • Enhanced Location management, information and triggers
    • Interconnection between 3GPP defined MC systems
    • Interworking with legacy systems

    MCPTT Enhancements:
    • Remotely initiated MCPTT call
    • Enhanced handling of MCPTT Emergency Alerts
    • Enhanced Broadcast group call
    • Updating pre-selected MC Service user profile
    • Temporary group call - user regroup
    • Functional alias identity for user and equipment
    • Multiple simultaneous users
    MCVideo Additions:
    • Video push
    • Video pull
    • Private call (on-network)
    • Broadcast Group Call
    • Ambient Viewing Call
    • Capability information sharing
    • Simultaneous Sessions
    • Use of MBMS transmission
    • Emergency and imminent peril private communications
    • Primary and Partner MC system interactions for MCVideo communications
    • Remote video parameters control capabilities

    MCData Additions:
    • MCData specific Location
    • Enhanced Status
    • Accessing list of deferred communications
    • Usage of MBMS
    • Emergency Alert
    • Data streaming
    • File Distribution (FD) (off-network)
    • IP connectivity

    Release-14 features will be available by end of September 2017 and many Release-15 features, that is being hurried due to 5G will be available by June 2018.

    For more details, follow the links below:

    Sunday, 10 May 2015

    LTE-Broadcast making a push while Terrestrial broadcast still popular as ever

    "TV isn't dying, it's having babies." This quote made my day. I have argued a few times in the past that terrestrial broadcasting will continue working and will be probably the most popular approach for a long time to come. The way things work with it may change. Multi-screen is one possible approach but you may have more interactions like 'red button functionality', etc.
    Anyway, in Europe 800MHz spectrum has been cleared for use by Mobile Broadband technologies (LTE mainly). 700MHz is planned to be cleared as well by 2020, as per the suggestion in Lamy report. The other UHF band from 470MHz to 694MHz would be left as it is until 2030, with a review planned in 2025.

    This has forced even big players like BBC to start looking at other mechanisms to deliver TV. While BBC3 was moved to online only, BBC is also exploring how to use LTE-Multicast to deliver content. It has been working to have its very popular iPlayer work with eMBMS.

    Embedded below is a presentation from Cambridge Wireless CWTEC 2015 conference.

    eMBMS is gaining popularity with its presence in lot more chipsets and even more trials. GSA report has shown that there are quite a few trials going on worldwide but the question remains about the business models. Most operators would not like to become content providers and compete with the incumbents in their markets. Having someone like BBC in the UK is helpful but not sure how many such options are available worldwide. Embedded below is the GSA presentation

    There were some nice pictures from MWC as can be seen above. Ericsson has a video as well (below) on how the app works.

    D-Link is also working on M2M modules that could be used in billboards to dynamically update the ads at very regular intervals. There is a video here that explains this further.

    Finally here is a Video from Visteon/Verizon that explains how LTE-Multicast can be used to deliver software updates in the connected car:

    Finally, here are couple of presentations that may interest you too:

    Thursday, 26 June 2014

    LTE-Broadcast: Reality check

    When I wrote my blog post about why the 'Cellular Broadcast may fail again' for the Cisco SP Mobility blog, I did not realise that this would become so popular and there would be so many people writing to me to tell me why and how my assumptions are wrong and how they plan to succeed. I have not yet received a successful reasoning on why people disagree with my article and where I am wrong.

    In the Video Over LTE Summit just concluded, I did not get a chance to see all the LTE-B presentations but the ones that I saw, were not convincing enough, except for one by Erol Hepsaydir, of '3' UK, that I explain in the end.

    Here is my presentation from that event:

    The conclusion is not self-explanatory so here it is in my own words.

    I am not opposed to the operators trying LTE-B out. I wish more operators do try and hopefully we can have a model where the technology can succeed. When operators succeed in a new technology, it benefits the whole mobile ecosystem directly or indirectly. The operators have to be prepared that they may not see any return. This should not discourage them because the learnings from this may benefit in something else. The customer and their loyalty is more important. We should try and provide them with a value addition rather than think of this as a new source of revenue. People are not interested in watching the same stuff they watch on the terrestrial TV on their small devices; unique and maybe tailored content would help. Finally, don't make the billing model too complex so the users shy away from trying this new technology.

    The final presentation of the event was delivered by Erol Hepsaydir of the UK operator '3'. He said that from their point of view, they are trying to have eMBMS to create additional capacity in the network. If they know that many people watch news on different apps and websites, they can offer this as a free service over broadcast. What this means is that they have gained customer loyalty and also free up the capacity for other users who are doing other data related activities. I think this is a very clever approach. He did mention though that they are only in the simulation stages and have not tried it out practically. 

    Thursday, 10 April 2014

    LTE-Broadcast of the operator, by the operator, for the operator!

    Heard an insightful talk from EE in the CW event this week. While I agree with the intentions and approaches, I still think there may be too many assumptions in the eMBMS business model. I have made my intentions known all but too well in my earlier blog post here.

    Some of the insights that I have gained in the last couple of months with regards to the way operators are planning to use the LTE broadcast is through the OTT Apps. Take for instance an OTT application like iPlayer or Hulu and some popular program is about to be broadcast, that program can be sent using LTE-B. Now some people may watch on the time (linear) and some may watch at a later time (non-linear or time-shifted). The App can be intelligent enough to buffer the program so there is no delay required when the user wants to watch it. This can open all sorts of issues like the user may have watched one episode on his device while the current one is being watched on his digital television. While the program is being buffered the battery and memory of the device is being consumed. How long should a program be stored on the device. There can be many other open issues.

    Another question I had was how would the users be billed for these things. Would it be free since the data was received over LTE-B. Matt Stagg from EE said that the users would be billed normally as if they received it in case of streaming. He was more pragmatic though. He clearly said that in the initial phase everything would have to be free. This will ensure that any technical issues are ironed out and at the same time the users become familiar with how all this works.

    Finally a point worth remembering, users prefer watching videos on their tablets. Most tablets are WiFi only which means the LTE-Broadcast wont work on it.

    The presentation is embedded as follows:

    Wednesday, 8 January 2014

    LTE-Broadcast (eMBMS) may fail again

    I recently wrote a blog post for the Cisco SP Mobility blog on why the Cellular Broadcast may fail again (complete article embedded below). My main point is that small screen devices are not really suitable for mobile TV kind of applications. The larger devices like tablets are but since they do not contain the (U)SIM card, its not possible for them to receive cellular broadcast signals.

    Anyway, I came across this picture below from the recent Ericsson Mobility report:

    This highlights my point that more people are now preferring to watch videos over the tablets as compared to the smaller smartphone screens. Even though the other diagrams in the article does show a significant amount of users using their smartphones for viewing movies and long clips, my belief is that this will reduce over the time as the tablet share increases

    A recent Business Insider article says that "One In Every 5 People In The World Own A Smartphone, One In Every 17 Own A Tablet". Once the users move to using bigger screens, their preferences on how they watch videos will definitely change.

    A real interesting chart would be to show users viewing habits based on the screen size. Phablets are generally classified as smartphones but can be substitutes for tablets in many scenarios. They could definitely help the Mobile TV viewing habits on the smartphones.

    Anyway, here is the complete article:

    Monday, 23 September 2013

    Push to talk (PTT) via eMBMS

    I was talking about push to share back in 2007 here. Now, in a recent presentation (embedded below) from ALU, eMBMS has been suggested as a a solution for PTT like services in case of Public safety case. Not sure if or when we will see this but I hope that its sooner rather than later. Anyway, the presentation is embedded below. Feel free to add your comments:

    Thursday, 9 May 2013

    eMBMS Physical layer aspects from T&M point of view

    Based on the success of the recent posts on eMBMS, here and here, this final post on this topic is a look at physical layer perspective from Test and Measurement point of view. Slides kindly provided by R&S

    A video of this is also available on Youtube, embedded below:

    Wednesday, 24 April 2013

    eMBMS Release-11 enhancements

    Continuing on the eMBMS theme. In the presentation in the last post, there was introduction to the eMBMS protocols and codecs and mention about the DASH protocol. This article from the IEEE Communications magazine provides insight into the working of eMBMS and what potential it holds.

    Monday, 22 April 2013

    eMBMS rollouts gathering steam in 2013

    Its been a while since I last posted something on eMBMS. Its been even longer that we saw anything official from 3GPP on eMBMS. Recently I have seen some operators again starting to wonder if eMBMS makes business sense, while the vendors and standards are still working hard on the technology.

    Not so long back, HEVC/H.265 codec was standardised. This codec helps transmission of the video using half the bandwidth. This means that it would be economical to use this for broadcast technologies. No wonder Nokia, Thompson and NTT Docomo are excited.

    Interesting picture from a Qualcomm presentation (embedded in the end) shows how different protocols fit in the eMBMS architecture. My guess would be that the HEVC  may be part of the Codecs.

    On the operators front, Korea Telecom (KT) has intentions for countrywide rollout. Korea is one of the very few countries where end users have embraced watching video on small form factors. Verizon wireless has already signalled the intention to rollout eMBMS in 2014; its working out a business case. Telenor Sweden is another player to join the band with the intention of adopting Ericsson's Multi screen technology.

    One of the main reasons for the lack of support for the 3G MBMS technology was not a compelling business case. Qualcomm has a whitepaper that outlines some of the potential of LTE Broadcast technology here. A picture from this whitepaper on the business case below:

    Finally, a presentation from Qualcomm research on eMBMS embedded below:

    Monday, 13 August 2012

    A Twitter discussion on eMBMS

    @zahidtg: Samsung has demoed eMBMS using Anritsu RTD system -  - But is any operator interested?

    Korean consumer electronics giant Samsung has successfully demonstrated the clear delivery of television broadcast signals over an LTE 4G wireless network.
    Samsung is using evolved Multimedia Broadcast Multicast Service (eMBMS) technology and has tapped test & measurement specialist Anritsu's Rapid Test Designer (RTD) and MD8430A to simulate the LTE network environment used for the demonstration. 
    eMBMS technology allows carriers to adjust coverage and capacity as needed, allowing for more efficient use of network resources in order to better handle the heavy traffic load that broadcast video would present. 
    Samsung is actively looking to add more content to the value proposition for its phones. It has deployed its own Hub strategy for its Galaxy line of smartphones, which includes a Music Hub, Movies Hub and Games Hub, all of which give the handset-maker a new incremental revenue stream. A TV Hub that could support live TV content in addition to on-demand episode downloads could add a compelling new wrinkle in that pseudo-walled garden approach. 
    Samsung is also instrumental in bringing mobile TV to market via the Dyle initiative for mobile DTV—a service that offers live broadcast feeds from local TV affiliates over separate, dedicated broadcast spectrum. No. 5 U.S. wireless carrier MetroPCS just went live with Dyle service and a Samsung mobile DTV-compatible smartphone.

    @KimKLarsen: Depends on whether an operator believes in the broadcast over mobile model. Mobile User trends seems not in favor at least in WEU.

    @zahidtg: I agree and thats why I dont think broadcast will work in the short term. Would be different is Apple were to create biz model:)

    @KimKLarsen: though the question is whether they (Apple/Google) really need eMBMS for executing such a business model ... I guess not really?!

    @KimKLarsen: I have a couple of beautiful white papers on satellite (w & wo terrestrial component) eMBMS using S-band together w Apple or Google

    @zahidtg: True. My point is that they are the ones who can create a new biz model on it, operators cant be bothered. Too much hassle.

    @KimKLarsen: too much hassle, too little new revenue, risky ROI, insufficient scale, etc.. an Apple or alike might overcome due to shear scale!

    @KimKLarsen: though w a satellite (w. city based terrestrial component) based eMBMS system you cover large landmass & pop & get the Scale!

    @Qualcomm_Tech: I think the best initial use case for #eMBMS is to selectivley use it as venue casting at stadiums/exhibitons etc.

    @kitkilgour: "ClipCasting" has been the main eMBMS use case - stadia, or catching up on your 1min news at stations

    @Qualcomm_Tech: True, Any content destined to venue users, incl. live/real-time can leverage eMBMS- huge capacity increase

    @KimKLarsen: I agree! Might be interesting! But can this really justify eMBMS as a service for mass adaption?

    @KimKLarsen: when will eMBMS be supported in Gobi? & when can we expect this to be standard in all LTE terminal devices?

    @kitkilgour: It's networks as well as devices. MBMS has always been hampered by needing to reach the cell edge ...

    @kitkilgour: ... with limited / no power control whilst minimising interference to others

    @KimKLarsen: great feedback! Thanks! Do you see a need for denser networks to deliver a uniform MBMS service than for standard data services?

    @KimKLarsen: one of the challenges we have had in nominal terrestrial MBMS designs have been link budget requirements! Any good sources?

    @Qualcomm_Tech: challenge’s been having enough penetration of multicast devices. Venue cast solves that problem #1000x

    @KimKLarsen: Sounds like Venue Cast is The Main Driver for eMBMS adoptation? (hmmm?) What's the Revenue Source? #42x

    @KimKLarsen: I don't understand how Venue Cast can Drive MC Device Uptake? The other way around more reasonable! #42x

    @Qualcomm_Tech: Target specific groups, eg season ticket holders & offer attractive device/content/plan bundles #1000x


    @zahidtg = Zahid Ghadialy
    @KimKLarsen = Dr. Kim Larsen
    @Qualcomm_Tech = Qualcomm_Tech
    @kitkilgour = Kit Kilgour

    In other news, Huawei Launches eMBMS Innovation Center to Develop LTE Solutions:

    Huawei, a leading global information and communications technology (ICT) solutions provider, today announced the launch of an enhanced Multimedia Broadcast Multicast Service (eMBMS) innovation center in Shenzhen in order to develop end-to-end eMBMS solutions and LTE applications. 
    eMBMS is a 3GPP R9 standard for mobile video that enables a higher transfer capacity over typical MBMS technologies. Huawei's eMBMS innovation center will focus on on-demand video services and broadcast information based on eMBMS. This will enrich LTE applications and accelerate the development of the eMBMS industry chain, which includes chipsets, devices, and network equipment.
    In addition to developing solutions, the innovation center will also serve as an experience center for operators. Video, mobile TV, and advertisements will be showcased via mobile smart devices employing Huawei's eMBMS solution. Global operators from Europe, Asia, the South Pacific and other regions have already visited the center to experience its LTE demonstrations.
    Huawei has been committed to the growing mobile video market since 2006. According to the Global mobile Supplier Association's (GSA) “Mobile Broadband Status Report”, over four billion people watch videos on YouTube every day. This large-scale usage is leading to increased revenue. According to a report from Global Industry Analysts, revenue from the mobile video market will reach USD30 billion by 2017. Huawei's eMBMS research team works closely with operators, chipset and device manufactures and other partners to further the development of the industry for the benefit of all end users.
    Huawei's LTE division has been committed to providing the best commercially performing network, the best end user experience through devices and innovative services, as well as end-to-end convergent solutions for helping operators with their business success. Huawei's eMBMS innovation center will push the development of mobile video well into the future.

    Friday, 11 May 2012

    Updated LTE Architecture with LCS and MBMS entities

    Here is an attempt to update the LTE Architecture with MBMS and Location Services (LCS) entities included

    You can also refer to the following old posts:

    Tuesday, 22 March 2011

    3GPP Official 'MBMS support in E-UTRAN' - Mar 2011

    Last month I blogged about the MBMS feature in Rel-9. The 3GPP official presentation on MBMS is now available. Embedded below:

    Presentation can be downloaded from Slideshare.

    This presentation was a part of Joint one hour session of 3GPP RAN and 3GPP CT on March 16th 2011, 11.00 am – 12.00 p.m. More on this coming soon.

    Monday, 21 February 2011

    MBMS in LTE Release-9

    From NTT Docomo Technical Journal:

    MBMS is a bearer service for broadcast/multicast transmission of data, to transmit the same information to all interested UEs in an area over a common bearer. Note that MBMS has been supported in UTRA since Release 6.

    LTE Release 9 supports basic MBMS functionality not requiring complex control. One of the main features is support for MBMS Single Frequency Network (MBSFN) transmission. With MBSFN transmission eNBs in the MBSFN area transmit the same signal simultaneously using the same time-frequency resource. The UE receives the combined signals as a single, strong signal, improving coverage and signal quality without much additional complexity in the UE. By applying MBSFN transmission, a 3GPP study concluded that to provide 95% coverage with a packet error rate of 1%, a spectral efficiency of 3 bit/s/Hz or greater can be achieved.

    The logical architecture for MBMS in LTE is shown in Figure 4. The MBMS gateway (GW) distributes data received from the Broadcast Multicast Service Center (BMSC) to the relevant eNBs by IP multicast. The Multi-Cell Multicast Coordination Entity (MCE) specifies the radio resources to be used by eNBs comprising the MBSFN and ensures that the content is synchronized. To support MBMS, logical channels, namely Multicast Traffic Channel (MTCH) and Multicast Control Channel (MCCH), and a transport channel, namely Multicast Channel (MCH), are defined (Figure 5).

    Sunday, 13 June 2010

    MBMS, Digital TV and IP Triple Play in China

    Apparently according to this report by Xuefei (Michael) Peng, MBMS is alive and kicking in China with around 200,000 users already. I cant find more info so if anybody who can fill more info is more than welcome.

    The government of mainland China has formulated a general plan to launch triple-play services, integrating telecom networks, broadcast and TV networks, and Internet together.

    From 2010 to 2012, China will focus on the trial integration of broadcast and TV services and telecom services (including Internet services), dealing with any related policies. From 2013 to 2015, based on the trial experience, China will promote the integration nationwide.

    In the coming five years, various sectors will prepare in different ways to meet the goals stated in the general plan. Telecom operators such as China Mobile, China Unicom, and China Telecom will invest more to promote IPTV services and accelerate FTTX deployment. Meanwhile, broadcast and TV operators will accelerate cable-TV network integration and interactive TV services development and will more actively develop value-added Internet services.

    Broadcast and TV operators are currently strong in video content and wireless broadcast, while telecom operators own two-way fixed-line networks, mobile networks, and Internet services.

    The differences between broadcast and TV operators across different regions and the uneven distribution of telecom fixed-line networks and mobile networks can offer cooperation opportunities.

    Notably, almost all provinces of China already have launched IPTV services. The total number of IPTV service users in China has exceeded 5 million. However, problems with IPTV content must be solved, and the price for IPTV services also needs to be lowered to attract more users and compete with digital TV.

    Meanwhile, the transformation of cable-TV networks from one way to two way has been sped up. Two-way cable-TV networks now cover over 24 million users. In the coming three years, broadcast and TV operators will invest over US$5 billion to continue to change 100 million one-way cable-TV links into two-way cable TV.

    Eventually, through cable-TV networks, broadcast and TV operators hope to run Internet access services. This has been in trial use in some provinces. In order to run Internet access services, however, broadcast and TV operators need to rent bandwidth from telecom operators, greatly increasing the potential cost of service.

    Another aspect of the triple play involves the conversion of mobile services to triple play. Mobile-phone TV is an emerging service in China. Up to now, mobile-phone TV services based on the China Multimedia Mobile Broadcasting (CMMB) standard have reached 1.5 million users. However, the current CMMB standard only supports one-way communication. So the users can only receive broadcast-TV programs via mobile.

    On the other hand, mobile services based on the broadcast multicast Multimedia Broadcast Multicast Service (MBMS) standard serve about 200,000 users. The growing 3G user base will convert to the MBMS standard. Additionally, the government policy will affect the mobile-phone TV market too. So it is not clear yet which mobile-phone TV standard will dominate the industry in the future.

    Monday, 11 January 2010

    Technologies and Standards for TD-SCDMA Evolutions to IMT-Advanced

    Picture Source:

    This is a summary of a paper from IEEE Communications Magazine, Dec 2009 issue titled "Technologies and Standards for TD-SCDMA Evolutions to IMT-Advanced" by Mugen Peng and Wenbo Wang of Beijing University of Posts and Telecommunications with my own comments and understanding.

    As I have blogged about in the past that China Mobile has launched TD-SCDMA network in China and the main focus to to iron out the basic problems before moving onto the evolved TD-SCDMA network. Couple of device manufacturers have already started working on the TD-HSPA devices. Couple of months back, 3G Americas published a whitepaper giving overview and emphasising the advantages of TDD flavour of LTE as compared to FDD. The next milestone is the IMT-Advanced that is under discussion at the moment and China has already proposed TD-LTE-Advanced which would be compatible with the TD-SCDMA technology.

    For anyone who does not know the difference between TDD, FDD and TD-SCDMA please see this blog.

    The TD-SCDMA technology has been standardised quite a while back but the rollout has been slow. The commercial TD-SCDMA network was rolled out in 2009 and more and more device manufacturers are getting interested in the technology. This could be due to the fact that China Mobile has a customer base of over 500 million subscribers. As of July 2009 over 100 device manufacturers were working on TD-SCDMA technology.

    The big problem with TD-SCDMA (as in the case of R99 3G) is that the practical data rate is 350kbps max. This can definitely not provide a broadband experience. To increase the data rates there are two different approaches. First is the Short Term Evolution (STE) and the other is Long Term Evolution (LTE).

    The first phase of evolution as can be seen in the picture above is the TD-STE. This consists of single carrier and multi-carrier TD-HSDPA/TD-HSUPA (TD-HSPA), TD-MBMS and TD-HSPA+.

    The LTE part is known as TD-LTE. There is a definite evolution path specified from TD-SCDMA to TD-LTE and hence TD-LTE is widely supported by the TD-SCDMA technology device manufacturers and operators. The target of TD-LTE is to enhance the capabilities of coverage, service provision, and mobility support of TD-SCDMA. To save investment and make full use of the network infrastructure available, the design of TD-LTE takes into account the features of TD-SCDMA, and keeps TD-LTE backward compatible with TD-SCDMA and TD-STE systems to ensure smooth migration.

    The final phase of evolution is the 4G technology or IMT-Advanced and the TD-SCDMA candidate for TD-LTE+ is TD-LTE-Advanced. Some mature techniques related to the TD-SCDMA characteristics, such as beamforming (BF), dynamic channel allocation, and uplink synchronization, will be creatively incorporated in the TD-LTE+ system.

    Some academic proposals were also made like the one available here on the future evolution of TD-SCDMA but they lacked the industry requirements and are just useful for theoretical research.

    The standards of TD-SCDMA and its evolution systems are supervised by 3GPP in Europe and by CCSA (Chinese Cellular Standards Association) in China. In March 2001 3GPP fulfilled TD-SCDMA low chip rate (LCR) standardization in Release 4 (R4). The improved R4 and Release 5 (R5) specifications have added some promising functions including HSDPA, synchronization procedures, terminal location (angle of arrival [AOA]-aided location), and so on.

    When the industry standardizations supervised by CCSA are focusing on the integration of R4 and R5, the N-frequency TD-SCDMA and the extension of HSDPA from single- to multicarrier are presented. Meanwhile, some networking techniques, such as N-frequency, polarized smart antenna, and a new networking configuration with baseband unit plus remote radio unit (BBU+RRU), are present in the commercial application of TD-SCDMA.


    For the first evolution phase of TD-SCDMA, three alternative solutions are considered. The first one is compatible with WCDMA STE, which is based on HSDPA/HSUPA technology. The second is to provide MBMS service via the compatible multicast broadcast single-frequency network (MBSFN) technique or the new union time-slot network (UTN) technique. The last is HSPA+ to achieve similar performance as LTE.

    On a single carrier, TD-HSDPA can reach a peak rate of 2.8 Mb/s for each carrier when the
    ratio of upstream and downstream time slots is 1:5. The theoretical peak transmission rate of a three-carrier HSDPA system with 16-quadrature amplitude modulation (QAM) is up to 8.4 Mb/s.

    Single-carrier TD-HSUPA can achieve different throughput rates if the configurations and parameters are varied, including the number of occupied time slots, the modulation, and the transport block size in bytes. Considering the complexity of a terminal with several carriers in TD-HSUPA, multicarrier is configured in the Node B, while only one carrier is employed in the terminal.

    In Rel-7 based TD-HSPA+, In order to match the performance of orthogonal frequency-division multiple access (OFDMA)-based TD-LTE systems, some advanced techniques are utilized, such as multiple-input multiple-output (MIMO), polarized BF, higher modulation and coding schemes (64-QAM is available), adaptive fast scheduling, multicarrier techniques, and so on. Theoretically, 64-QAM can improve performance by a factor of 1.5 compared to the current 16-QAM; for single-carrier the peak rate reaches 4.2 Mb/s, and three-carrier up to 12.6 Mb/s.

    For the MIMO technique, double transmit antenna array (D-TxAA), based on the pre-coding method at the transmitter, has been employed in frequency-division duplex (FDD)-HSPA+ systems, while selective per antenna rate control (S-PARC), motivated by the Shannon capacity limit for an open loop MIMO link, has been applied in TD-HSPA+ systems.


    The TD-SCDMA LTE program was kicked off in November 2004, and the LTE demand report was approved in June 2005. The LTE specified for TD_SCDMA evolution is named TD-LTE.

    LTE systems are supposed to work in both FDD and TDD modes. LTE TDD and FDD modes have been greatly harmonized in the sense that both modes share the same underlying framework, including radio access schemes OFDMA in downlink and SC-FDMA in uplink, basic subframe formats, configuration protocols, and so on.

    TD-LTE trials have already started last year with some positive results.


    IMT-Advanced can be regarded as a B3G/4G standard, and the current TD-SCDMA standard migrating to IMT-Advanced can be regarded as a thorough revolution. TD-LTE advanced (TD-LTE+) is a good match with the TD-SCDMA revolution to IMT-Advanced.

    It is predicted that the future TD-SCDMA revolution technology will support data rates up to approximately 100 Mb/s for high mobility and up to approximately 1 Gb/s for low mobility such as nomadic/local wireless access.

    Recently, some advanced techniques have been presented for TD-LTE+ in China, ranging from the system architecture to the radio processing techniques, such as multi-user (MU)-BF, wireless relaying, and carrier aggregation (CA).

    For MU-BF see the paper proposed by Huawei, CHina Mobile and CATT here (

    For Wireless Relaying see the ZTE paper here (

    To achieve higher performance and target peak data rates, LTE+ systems should support bandwidth greater than 20 MHz (e.g., up to 100 MHz). Consequently, the requirements for TD-LTE+ include support for larger transmission bandwidths than in TD-LTE. Moreover, there should be backward compatibility so that a TD-LTE user can work in TD-LTE+ networks. CA is a concept that can provide bandwidth scalability while maintaining backward compatibility with TD-LTE through any of the constituent carriers, where multiple component carriers are aggregated to the desired TD-LTE+ system bandwidth. A TD-LTE R8 terminal can receive one of these component carriers, while an TD-LTE+ terminal can simultaneously access multiple component carriers. Compared to other approaches, CA does not require extensive changes to the TD-LTE physical layer structure and simplifies reuse of existing implementations. For more on Carrier Aggregation see CATT, LGE and Motorola paper here (

    Finally, there are some interesting developments happening in the TD-SCDMA market with bigger players getting interested. Once a critical mass is reached in the number of subscribers as well as the manufacturers I wouldnt be surprised if this technology is exported beyond the Chinese borders. With clear and defined evolution path this could be a win-win situation for everyone.