Multipoint HSDPA / HSPA

The following is from 3GPP TR 25.872 - Technical Specification Group Radio Access Network; HSDPA Multipoint Transmission:

HSPA based mobile internet offerings are becoming very popular and data usage is increasing rapidly. Consequently, HSPA has begun to be deployed on more than one transmit antenna or more than one carrier. As an example, the single cell downlink MIMO (MIMO-Physical layer) feature was introduced in Release 7. This feature allowed a NodeB to transmit two transport blocks to a single UE from the same cell on a pair of transmit antennas thus improving data rates at high geometries and providing a beamforming advantage to the UE in low geometry conditions. Subsequently, in Release-8 and Release-9, the dual cell HSDPA (DC-HSDPA) and dual band DC-HSDPA features were introduced. Both these features allow the NodeB to serve one or more users by simultaneous operation of HSDPA on two different carrier frequencies in two geographically overlapping cells, thus improving the user experience across the entire cell coverage area. In Release 10 these concepts were extended so that simultaneous transmissions to a single UE could occur from four cells (4C-HSDPA).

When a UE falls into the softer or soft handover coverage region of two cells on the same carrier frequency, it would be beneficial for the non-serving cell to be able to schedule packets to this UE and thereby improving this particular user’s experience, especially when the non-serving cell is partially loaded. MultiPoint HSDPA allows two cells to transmit packets to the same UE, providing improved user experience and system load balancing. MultiPoint HSDPA can operate on one or two frequencies.

Click to enlarge

There is also an interesting Qualcomm Whitepaper on related topic that is available to view and download here. The following is from that whitepaper:

The simplest form of Multipoint HSPA, Single Frequency Dual Cell HSPA (SFDC-HSPA), can be seen as an extension to the existing DC-HSPA feature. While DC-HSPA allows scheduling of two independent transport blocks to the mobile device (UE) from one sector on two frequency carriers, SFDC-HSPA allows scheduling of two independent transport blocks to the UE from two different sectors on the same carrier. In other words, it allows for a primary and a secondary serving cell to simultaneously send different data to the UE. Therefore, the major difference between SFDC-HSPA and DC-HSPA operation is that the secondary transport block is scheduled to the UE from a different sector on the same frequency as the primary transport block. The UE also needs to have receive diversity (type 3i) to suppress interference from the other cell as it will receive data on the same frequecny from multiple serving cells.Figure 1 llustrates the high-level concept of SFDC-HSPA.

In the case where the two sectors involved in Multipoint HSPA transmission belong to the same NodeB (Intra-NodeB mode), as illustrated in Figure 2, there is only one transmission queue maintained at the NodeB and the RNC. The queue management and RLC layer operation is essentially the same as for DC-HSPA.

In the case where the two sectors belong to different NodeBs (Inter-NodeB mode), as illustrated in Figure 2, there is a separate transmission queue at each NodeB. RLC layer enhancements are needed at the RNC along with enhanced flow control on the Iub interface between RNC and NodeB in order to support Multipoint HSPA operation across NodeBs. These enhancements are discussed in more detail in Section 4. In both modes, combined feedback information (CQI and HARQ-ACK/ NAK) needs to be sent on the uplink for both data streams received from the serving cells. On the uplink, the UE sends CQIs seen on all sectors using the legacy channel structure, with timing aligned to the primary serving cell.

When two carriers are available in the network, there is an additional degree of freedom in the frequency domain. Dual Frequency Dual Cell HSPA (DFDC-HSPA) allows exploiting both frequency and spatial domains by scheduling two independent transport blocks to the UE from two different sectors on two different frequency carriers. For a DC-HSPA capable UE, this is equivalent to having independent serving cells on the two frequency carriers. In Figure 3, UE1 is in DC-HSPA mode, whereas UE2 is in DFDC-HSPA mode.

Dual Frequency Four-Cell HSPA (DF4C-HSPA) can be seen as a natural extension of DFDC-HSPA, suitable for networks with UEs having four receiver chains. DF4C-HSPA allows use of the four receiver chains by scheduling four independent transport blocks to the UE from two different sectors on two different frequency carriers. DF4C-HSPA is illustrated in Figure 4.

Like SFDC-HSPA; DFDC-HSPA and DF4C-HSPA can also be intra-NodeB or inter-NodeB, resulting in an impact on transmission queue management, Iub flow control and the RLC layer.

Advantages of Multipoint transmission:

* Cell Edge Performance Improvement

* Load balancing across sectors and frequency carriers

* Leveraging RRU and distributed NodeB technology

Multipoint HSPA improves the performance of cell edge users and helps balance the load disparity across neighboring cells. It leverages advanced receiver technology already available in mobile devices compatible with Release 8 and beyond to achieve this. The system impact of Multipoint HSPA on the network side is primarily limited to software upgrades affecting the upper layers (RLC and RRC).

See also: FS_HSDPA_MP_TX: Study on HSDPA Multipoint Transmission

2020: Radio and Mobile Broadband (MBB) Beyond 4G

An interesting presentation and whitepaper from Nokia Siemens Networks embedded below:

Mobile Broadband Beyond 4G

View more presentations from Nokia Siemens Networks

Nokia siemens networks beyond 4 g white paper online 20082011

View more documents from Nokia Siemens Networks

Related post: 2020: More than 50 Billion connected devices - Ericsson

Mobility Robustness Optimization to avoid Handover failures

The following is from 4G Americas Whitepaper on SON:

Mobility Robustness Optimization (MRO) encompasses the automated optimization of parameters affecting active mode and idle mode handovers to ensure good end-user quality and performance, while considering possible competing interactions with other SON features such as, automatic neighbor relation and load balancing.

There is also some potential for interaction with Cell Outage Compensation and Energy Savings as these could also potentially adjust the handover boundaries in a way that conflicts with MRO. While the goal of MRO is the same regardless of radio technology namely, the optimization of end-user performance and system capacity, the specific algorithms and parameters vary with technology.

The objective of MRO is to dynamically improve the network performance of HO (Handovers) in order to provide improved end-user experience as well as increased network capacity. This is done by automatically adapting cell parameters to adjust handover boundaries based on feedback of performance indicators. Typically, the objective is to eliminate Radio Link Failures and reduce unnecessary handovers. Automation of MRO minimizes human intervention in the network management and optimization tasks.

The scope of mobility robustness optimization as described here assumes a well-designed network with overlapping RF coverage of neighboring sites. The optimization of handover parameters by system operators typically involves either focused drive-testing, detailed system log collection and postprocessing, or a combination of these manual and intensive tasks. Incorrect HO parameter settings can negatively affect user experience and waste network resources by causing HO ping-pongs, HO failures and Radio Link Failures (RLF). While HO failures that do not lead to RLFs are often recoverable and invisible to the user, RLFs caused by incorrect HO parameter settings have a combined impact on user experience and network resources. Therefore, the main objective of mobility robustness optimization should be the reduction of the number of HO-related radio link failures. Additionally, sub-optimal configuration of HO parameters may lead to degradation of service performance, even if it does not result in RLFs. One example is the incorrect setting of HO hysteresis, which may results in ping-pongs or excessively delayed handovers to a target cell. Therefore, the secondary objective of MRO is the reduction of the inefficient use of network resources due to unnecessary or missed handovers.

Most problems associated with HO failures or sub-optimal system performance can ultimately be categorized, as either too-early or too-late triggering of the handover, provided that the required fundamental network RF coverage exists. Thus, poor HO-related performance can generally be categorized by the following events:

* Intra-RAT late HO triggering

* Intra-RAT early HO triggering

* Intra-RAT HO to an incorrect cell

* Inter-RAT too late HO

* Inter RAT unnecessary HO

Up to Release 9, a UE is required to send RLF report only in case of successful RRC re-establishment after a connection failure. Release 10 allows support for RLF reports to be sent even when the RRC reestablishment does not succeed. The UE is required to report additional information to assist the eNB in determining if the problem is coverage related (no strong neighbors) or handover problems (too early, too late or wrong cell). Furthermore, Release 10 allows for precise detection of too early / wrong cell HO.

Benefit of 1.4GHz for Mobile Downlink

Significant benefits could flow from use of 1.4 GHz band for a supplemental mobile downlink for enhanced multi-media and broadband services, according to a study by Plum Consulting conducted for Ericsson and Qualcomm.

The study by Plum Consulting shows that using the 1.4 GHz band (i.e. 1452-1492 MHz also called 1.5 GHz by the European Parliament or the L-band by the CEPT) for terrestrial supplemental mobile downlink could generate a net present value for Europe of as much as EUR54 billion over a 10 year period.

The band is currently allocated for use by digital audio broadcasting (DAB) services in most European countries -- part of the band is allocated to terrestrial networks and part is allocated to satellite networks. None of these services have developed in the band. Rather in all countries in Europe the satellite part of the band is unused and this is also the case in the terrestrial component in most countries.

There could be up to eight times as much data being downloaded than is being uploaded in mobile networks. This imbalance is expected to grow, as rich mobile content is increasingly made available and as consumer demand continues to soar. The study found that the use of the 1.4 GHz band as a supplemental downlink band for mobile applications is shown to drastically ease capacity, to enable considerably higher user data rates, to substantially enhance the user experience and to provide significant economic benefits.

The value of releasing the 1.4 GHz band depends on whether other substitute spectrum may become available in the next 5 to 10 years. Starting from today, all countries in Europe have planned or are planning to release the 800 MHz and 2.6 GHz bands in the next two years. There is equipment available for use in both bands and services are already deployed in some countries.

Which other bands might be released over the next 10-15 years? Table 3-2 gives a number of candidate bands, ordered by the likely timing for release, including the 1.4 GHz band for completeness. In each case, we summarise the current status of the band, initiatives that suggest it might be a candidate for future release and our views on the possible timing of deployment based on the difficulty of clearing the band and the harmonisation/standardisation initiatives that would need to be undertaken before equipment would be mass produced for the band.

The white paper is embedded below for reference:

Economic study of the benefits from use of 1.4 GHz for a supplemental mobile downlink

View more documents from Zahid Ghadialy

3GPP Femtocells: Architecture and Protocols

3GPP Femtocells: Architecture and Protocols

View more documents from All About 4G

More than 50 Billion Connected Devices

I blogged about the 50 Billion connected devices as predicted by Ericsson last year. With the promised 'Internet of things' and 'connected world' we may see 50 billion devices not too far in the near future. Here is a recent whitepaper from Ericsson on this topic.

Vision 2020 - 50 Billion Connected Devices - Ericsson from Ericsson France

4G Mobile Broadband Evolution: 3GPP Release-10 and Beyond

New Report from 4G Americas:

4G Mobile Broadband Evolution: 3GPP Release 10 and Beyond - HSPA+ SAE/LTE and LTE-Advanced provides detailed discussions of Release 10, including the significant new technology enhancements to LTE/EPC (called LTE-Advanced) that were determined in October 2010 to have successfully met all of the criteria established by the International Telecommunication Union Radiotelecommunication Sector (ITU-R) for the first release of IMT-Advanced. IMT-Advanced, which includes LTE-Advanced, provides a global platform on which to build next generations of interactive mobile services that will provide faster data access, enhanced roaming capabilities, unified messaging and broadband multimedia. The paper also provides detailed information on the introduction of LTE-Advanced and the planning for Release 11 and beyond. Release 10 is expected to be finalized in March 2011, while work on Release 11 will continue through the fourth quarter of 2012.

White paper embedded below and is available to view and download from the 3G4G website.

4G Mobile Broadband Evolution: 3GPP Release-10 and Beyond

View more documents from Zahid Ghadialy.

Heterogeneous LTE Networks and Inter-Cell Interference Coordination

An interesting paper that is more of a background to my earlier post here is available from Nomor Research and is embedded below.

Heterogeneous LTE Networks and Inter-Cell Interference Coordination

View more documents from Zahid Ghadialy.

This paper is available to download from here.

Voice over LTE – a step towards future telephony (Ericsson Whitepaper)

The Fact boxes in the Appendix give a very good quick overview of how different technologies work with VoLTE.

Voice over LTE – a step towards future telephony

View more documents from Zahid Ghadialy

An Intellectual Property Rights Primer

Page 5-8 is a very good starting point to understand the IPR issues surrounding LTE.

The Essentials of Intellectual Property - Sep 2010

View more documents from Zahid Ghadialy.

An accompanying video and download information is available on Ericsson's website here.

Cell search and cell selection in UMTS LTE

Cell search and cell selection in UMTS LTE

View more documents from All About 4G.

Japan M-Commerce Morgan Stanley report

Interesting reading.Japan M-Commerce Morgan Stanley report

View more presentations from Zahid Ghadialy.

EDGE evolution to REDHOT

EDGE is more than three times as efficient as GSM/GPRS in handling packet-switched data. Using EDGE, operators can support 3x more subscribers than GPRS, either by increasing the data rate per subscriber to 300 kbps, according to network & device capabilities, or adding voice capacity. EDGE uses the same TDMA frame structure, logic channel and 200 kHz carrier as GSM; existing cell plans remain intact. No change is needed in the core network. Neither new spectrum nor a new operating licence is needed. EDGE is a mature, mainstream global technology which allows operators to compete, to protect investments/assets, and stimulate growth of mobile multimedia services. Upgrading to EDGE is a natural step for operators to offer high performance mobile data services over GSM.

The performance of EDGE has improved steadily since its introduction in the market in 2003, and today offers users the possibility of data speeds up to 250kbps, with a latency of less than 150ms. This is sufficient for any current data service to be attractive to customers. According to GSA’s latest EDGE Fact Sheet (August 19, 2010 and available as a free download from www.gsacom.com) over 80% of GSM/GPRS operators globally have committed to deploying EDGE in their networks. 531 GSM/EDGE networks are in commercial service in 196 countries, and thousands of EDGE-capable user devices are launched.

A key part of the evolution is the opportunity to deploy more than a single RF carrier. Downlink Dual Carrier (DLDC) is the first step in evolving EDGE, doubling data rates to 592 kbps on existing EDGE-capable networks.

Downlink speed quadrupled:

up to 1.2 Mbps per user initially

(the standard enables up to 1.9 Mbps per user)

• Dual Carrier first phase implementation 10 timeslots per user; standard enables up to 16 timeslots per user

• EGPRS-2 DL (REDHOT) level B maximum 118.4 kbps per timeslot

Uplink speed up to 474 kbps per user

(the standard enables up to 947 kbps per user)

• EGPRS-2 UL (HUGE) level B with maximum 118.4 kbps per timeslot

• Peak implementation today 4 timeslots per user (standard enables up to 8 timeslots per user)

The EGPRS-2 feature is expected in the market in 2012.

More information is available in the GSA Report 'EDGE Evolution' released on Aug 23 2010. Available to download from GSACOM here.

100+ LTE Commitments, 22 commercial networks planned for 2010

The Global mobile Suppliers Association (GSA) has published an update to its Evolution to LTE report which confirms that 101 firm LTE network deployments are in progress or planned in 41 countries. The number of network commitments is 71% higher than GSA reported in a similar survey six months ago.

This figure includes three LTE systems which have launched commercial service – in Sweden, Norway, and Uzbekistan. GSA anticipates up to 22 LTE networks will be in commercial service by end 2010.

Another 31 operators are engaged in various LTE pilot trials and technology tests (these are referred to as pre-commitment trials). Taken together, it means that 132 operators are now investing in LTE in 56 countries.

The GSA Evolution to LTE report covers both LTE FDD and LTE TDD modes, and provides a summary of the market situation in each country, including operator activities and plans, spectrum requirements and developments, information on the growing eco-system including device and platforms availability, performance and interoperability trials results, key industry trends and forecasts.

LTE networks are now being deployed for commercial service or planned in Armenia, Australia, Austria, Bahrain, Brazil, Canada, Chile, China, Denmark, Estonia, Finland, France, Germany, Hong Kong, Hungary, India, Ireland, Italy, Japan, Jordan, Kazakhstan, Kuwait, Latvia, Libya, Netherlands, New Zealand, Norway, Portugal, Russia, Saudi Arabia, Singapore, South Africa, South Korea, Sweden, Switzerland, Taiwan, The Philippines, UAE, UK, USA, and Uzbekistan.

Governments around the world are preparing the way to ensure the availability of spectrum to support delivery of next generation mobile broadband services for the mass market, by allocating or preparing for the release of new spectrum such as 2.6 GHz, and in the digital dividend (700 MHz, 800 MHz) bands, or re-farming existing spectrum e.g. 900 MHz, 1800 MHz, etc. or facilitating a combination of new and re-farmed bands. The report notes that several trials licenses have been granted in many countries to allow operators to familiarize with the technology, capabilities and performance aspects. A number of tenders for spectrum licenses have been announced or confirmed in recent weeks for the granting of spectrum suitable for LTE deployments, including in Australia, Brazil, Chile, Poland, and the UK. Several auctions are scheduled for completion in the next few months.

LTE is the next generation mobile broadband technology of choice and the natural evolutionary step for GSM/WCDMA-HSPA operators and also for many leading CDMA operators around the world. A leading WiMAX operator has also recently announced the company has decided to shift to LTE.

While the majority of LTE deployments today are using the FDD mode, the report confirms significant operator interest in the TDD mode. LTE FDD and LTE TDD are complementary technologies and standardized by 3GPP. A number of key technology milestones have been demonstrated in recent weeks which confirm how the LTE TDD system is maturing towards commercialization. The recently concluded BWA spectrum auction in India has paved the way for early and large scale introduction of TDD LTE into the world’s fastest developing market.

Alan Hadden, President, GSA said: “Our latest Evolution to LTE report shows how the pace towards LTE has quickened, which is easy to see from the increasing numbers of operator trials and announcements, and positive actions by several regulatory bodies around the world”.

The GSA Evolution to LTE report (August 26, 2010) is available as a free download to registered site users at http://www.gsacom.com/gsm_3g/info_papers.php4 and is embedded below

LTE Network Commitments Aug 2010

View more documents from Zahid Ghadialy.

Mobile Developer Economics 2010 and Beyond

A new report "Mobile Developer Economics 2010 and Beyond", offers many new insights into mobile developer mindshare, and analysis into every touch point of the developer journey, from platform selection to monetisation. The research is based on a set of benchmarks and a survey across 400+ developers globally, segmented into 8 major platforms: iOS (iPhone), Android, Symbian, BlackBerry, Java ME, Windows Phone, Flash Lite, and mobile web.

In terms of developer mindshare, our research shows that Symbian and Java ME, which dominated the developer mindshare pool until 2008, have been superceded by the Android and iPhone platforms. Despite Symbian remaining in the pole position in terms of smartphone market penetration, ‘out-shipping’ iPhone 4 to 1 and Android many-times to 1, the signs of dissatisfaction with the way the Symbian platform has evolved have long been evident.

Indeed Android stands out as the top platform according to developer experience, with close to 60 percent of developers having recently developed on Android, assuming an equal number of developers with experience on each of eight major platforms. iOS (iPhone) follows closely as the next most popular platform, outranking both Symbian and Java ME, which until 2008 were in pole position.

The report can be downloaded from here and is embedded below for convenience

Mobile Developer Economics 2010 Report

View more documents from Zahid Ghadialy.

GSA report on Evolution to LTE

Global mobile Suppliers Association (GSA) published a report on "Evolution to LTE" which is available on their website here to download.

The report starts with the need for LTE and emphasises its importance with regards to the Mobile Broadband take off. It goes on to encourage the operators to embrace LTE and lists the operators that have committed to LTE roll out.

As of April 2010:

• 64 networks in 31 countries have committed to LTE network rollout.
• Upto 22 LTE networks would be in service end of 2010
• 39 or more LTE networks will be in service end of 2012

Spectrum is another area of focus of this report. Along with 2.6GHz, 700MHz will probably be used in Americas, New Zealand and India. 800 MHz and 900 MHz will probably be available and used in Europe.

Finally with LTE being rolled out, it would be easy to upgrade to LTE-Advanced when the standards are finalised in Release-10.

For people interested in this report and topics, the following related presentations are available from GSA:

• Digital Dividend Update - March 2010
• UMTS900 Global Status - March 2010
• Spectrum for LTE Mobile Broadband - Sep. 2009
• From TD-SCDMA to TD-LTE - Sep. 2009
• Low Frequency Options for Mobile Broadband - Sep. 2009
• UMTS 900 case study - June 2009

3G Americas Publishes New Report on Technology choices for Mobile Broadband

3G Americas, a wireless industry trade association representing the GSM family of technologies including LTE, announced that it has published its highly anticipated resource report on 3rd Generation Partnership Project (3GPP) standards and their evolution to IMT-Advanced, or 4G. The white paper, 3GPP Mobile Broadband Innovation Path to 4G: Release 9, Release 10 and Beyond: HSPA+, SAE/LTE and LTE-Advanced, provides in-depth examination of 3GPP technology standards from a technical, business and applications standpoint.

“The 3GPP technology standards deliver mobile connectivity to more than 4 billion users worldwide today and have been developed to continue evolving to higher levels of performance with mobile broadband innovation,” said Chris Pearson, president of 3G Americas. “GSM operators can choose to evolve their networks in ways that best suit their assets and business environments with benefits that offer flexibility, scalability and economic advantages, whether they choose HSPA+ or LTE.”

UMTS-HSPA is the world’s leading 3G technology and is the preferred choice for the majority of wireless operators and subscribers today and into the future. The global demand for wireless data services continues to drive the rapid growth of HSPA technology with 303 commercial HSPA networks and over 454 million UMTS-HSPA subscriptions reported at the end of 2009 by Informa Telecoms & Media. Informa has further projected that by year-end 2012, worldwide subscriptions to UMTS-HSPA will reach nearly 1.4 billion; by year-end 2013, global UMTS-HSPA subscriptions are expected to exceed 2 billion, rising to 2.8 billion by the end of 2014. GSM-UMTS-HSPA subscriptions provide the foundation for future evolutions to 3GPP Release 9, Release 10 and beyond with HSPA+, LTE and LTE-Advanced.

“Wireless data consumption is increasing faster now than ever before,” said Adrian Scrase, 3GPP Head of Mobile Competence Center. “Smartphone usage is experiencing higher volumes and the superior user experience offered by such devices is resulting in quickly rising demand and escalating use of wireless data applications. This is consequently driving the need for continued innovations that are supported by the efficient and successful 3GPP technology path.”

3GPP Mobile Broadband Innovation Path to 4G: Release 9, Release 10 and Beyond: HSPA+, SAE/LTE and LTE-Advanced, is a comprehensive resource intended to assist members of the wireless industry as well as interested members of the general public in understanding details of the work in 3GPP on Release 9 and Release 10. In addition, the report further describes the features of Release 8 that were closed in March 2009.

Release 9, which is targeted for completion by March 2010, will provide increased feature functionality and performance enhancements to both HSPA and LTE. The report reviews additional multi-carrier and MIMO options for HSPA and features and enhancements to support emergency services, location services and broadcast services for LTE. Other Release 9 enhancements include those to support Home NodeB/eNodeB (i.e. femtocells), Self-Organizing/Self-Optimizing Networks (SON) and the evolution of the IP Multimedia Subsystem (IMS) architecture.

LTE will serve to unify the fixed and mobile broadband worlds. As an all IP-based technology, LTE will allow expansion of the Internet experience on mobile devices and deliver multimedia content to the screen of choice. The vast majority of leading operators, device and infrastructure manufacturers support LTE as the mobile broadband technology of the future and, according to Informa Telecoms & Media, 130 global operators have announced trials or intentions to evolve their networks to LTE. Two commercial networks have already been launched in Norway and Sweden by TeliaSonera in 2009 and as many as 20 will be launched in 2010.

“All roads lead to LTE – for GSM, CDMA, newly licensed and potentially even WiMAX mobile operators,” Pearson added. “The appeal of the 3GPP technology roadmap is no longer suited for only GSM operators.”

While work for Release 9 is nearing completion, significant progress has already been made in 3GPP on work for Release 10, which includes LTE-Advanced. In fact, 3GPP already submitted a proposal in October 2009 based on LTE-Advanced for the IMT-Advanced evaluation and certification process led by the International Telecommunication Union (ITU). The ITU has defined requirements that will officially define and certify technologies as IMT-Advanced, or 4G, and is expected to evaluate submitted proposals by standards organizations for potential certification in the 2010 timeframe; certified 4G/IMT-Advanced technology specifications are projected to be published by early 2011.

As part of Release 10, some of the key LTE-Advanced technology enhancements include carrier aggregation, multi-antenna enhancements and relays. Assuming LTE-Advanced is certified to be IMT-Advanced compliant, 3GPP targets completion of the Release 10 specification by year-end 2010.

“The white paper by 3G Americas provides an excellent overview of the work by 3GPP in determining the standards on the path to 4G,” Scrase said.

The popular white paper, 3GPP Mobile Broadband Innovation Path to 4G: Release 9, Release 10 and Beyond: HSPA+, SAE/LTE and LTE-Advanced, was written collaboratively by members of 3G Americas and is available for free download here.