Wednesday 9 July 2008
Updated Paper on 3GPP Rel 7 and Rel 8 from 3G Americas
UMTS Evolution from 3GPP Release 7 to Release 8: HSPA and SAE/LTE offers a further review of 3GPP Release-7 (Rel-7) upon its completion in the technology standardization process and an introduction to the improved features of 3GPP Release 8 (Rel-8). The paper explores the growing demands for wireless data and successes for a variety of wireless applications, the increasing Average Revenue per User (ARPU) for wireless services by operators worldwide, recent developments in 3GPP technologies by several leading manufacturers, and 3GPP technology benefits and technical features.
Upon the finalization of the Rel-8 standard later this year, 3G Americas will publish a new white paper on the 3GPP standards that will include the completion of Rel-7 HSPA+ features, voice over HSPA, SAE/EPC (Evolved Packet Core) specification and Common IMS among other new developments and features. Since HSPA+ enhancements are fully backwards compatible with Rel-99/Rel-5/Rel-6, the upgrade to HSPA+ has been made smooth and evolutionary for GSM operators. Additionally, Rel-7 standardizes Evolved EDGE with continuing development in Rel-8 which will improve the user experience across all wireless data services by reducing latency and increasing data throughput and capacity. Finalization of the Rel-8 standard by the end of this year will further progress market interest in commercial deployment of LTE. Leading operators worldwide are announcing their plans to deploy LTE as early as 2010 with trials already occurring today.
The popular white paper UMTS Evolution from 3GPP Release 7 to Release 8: HSPA and SAE/LTE was written collaboratively by members of 3G Americas and is available for free download here.
Tuesday 17 June 2008
Flatter Architecture from Nokia-Siemens Network
In its bid to overtake Ericsson AB and become the world’s top radio access infrastructure supplier in terms of revenue, Nokia Siemens Networks believes its approach to all-IP flat architecture on 3G networks will give it an edge. Nokia Siemens says operators do not have to wait for LTE, to get the benefits of an all-IP architecture, and it is the only vendor that currently champions a flat 3G radio access network (RAN) approach.
As mobile data traffic continues to surge, operators are considering how to adopt flat, all-IP architectures in their 3G networks before the advent of 4G in order to gain lower latency, lower cost per bit, support for multiple access networks, and preparation for next-generation networks. But there are different ways to implement such architectures, and just how operators arrive at a flatter data network architecture is hotly debated.
Nokia Siemens has put its money on a flat RAN approach for high-speed packet access (HSPA) and the coming HSPA+ standard, in addition to its support for the Direct Tunnel architecture.
In a flat RAN architecture, the radio network controller (RNC) is integrated into the Node B so that the base station communicates directly with the Gateway GPRS Support Node (GGSN).
But there are as many benefits as drawbacks to flat 3G RANs, which makes it a controversial approach, according to the recent Heavy Reading report, "Flat IP Architectures in Mobile Networks: From 3G to LTE."
With flat RANs, some of the benefits include lower latency for data applications, lower operational costs due to fewer nodes to maintain and manage, augmented data capacity through a data network overlay, and good preparation for so-called 4G LTE/SAE (System Architecture Evolution), which uses a similar functional architecture. Also, costs won’t grow in line with data traffic growth, because operators won’t have to deploy extra RNC and SGSN capacity as traffic increases.
It may be challenging to integrate the RNC into a Node B. RNCs are critical to supporting macro-diversity in mobile networks, which enables mobile handsets to communicate with multiple base stations on the uplink and allows operators to deploy fewer base stations. NSN’s flat RAN architecture supports this feature, but in an unorthodox way, according to the Heavy Reading report.
So far, Nokia Siemens has three customers using its Internet HSPA (I-HSPA) flat RAN solution: Stelera Wireless and TerreStar Neworks in the U.S. and T-2 in Slovenia. And Mobilkom Austria AG & Co. KG recently trialed the solution.
Nokia Siemens’ Rouanne explains that flat 3G RANs aren’t necessary when there is just “medium” data traffic, but are best suited when operators have big data traffic volumes. “Those networks that are starting to be under pressure with traffic are coming to us and wanting to direct traffic directly to the Internet,” he says.
Even though Nokia Siemens is the only vocal supporter of flat 3G RANs right now, Brown says the strategy isn’t risky, but it’s “forward-looking.”
And a flat 3G RAN can set up an operator to be ready for the shift to LTE with its inherent flat architecture.
- Cost efficient scaling for Mobile Broadband deployments
- Increased flexibility in terms of network topology
- Allows the SGSN node to be optimized for control plane
- Specifications part of 3GPP rel-7
- Designed for operation in legacy (GGSN/UTRAN) networks
- First step towards the SAE architecture
- Reduce the number of network elements in the data path to lower operations costs and capital expenditure
- Partially decouple the cost of delivering service from the volume of data transmitted to align infrastructure capabilities with emerging application requirements
- Minimize system latency and enable applications with a lower tolerance for delay; upcoming latency enhancements on the radio link can also be fully realized
- Evolve radio access and packet core networks independently of each other to a greater extent than in the past, creating greater flexibility in network planning and deployment
- Develop a flexible core network that can serve as the basis for service innovation across both mobile and generic IP access networks
- Create a platform that will enable mobile broadband operators to be competitive, from a price/performance perspective, with wired networks
Sunday 8 June 2008
3GPP Selects Femtocell Architecture
The 3GPP wants to have the new standard done by the end of this year, which appears to be an aggressive time schedule given the fact that vendors had various approaches to building a femtocell base station. The agreed upon architecture follows an access network-based approach, leveraging existing standards, called IU-cs and Iu-ps interfaces, into the core service network. The result is a new interface called Iu-h.
The architecture defines two new network elements, the femtocell and the femtocell gateway. Between these elements is the new Iu-h interface. This solution was backed by Alcatel-Lucent, Kineto Wireless, Motorola and NEC.
All of the femtocell vendors must go back and change their access point and network gateway equipment to comply with the new standard interface.
All femtocell vendors will have to make changes to their access points. Alcatel-Lucent, Motorola, NEC, and those that already use Kineto's GAN approach, such as Ubiquisys, will have the least work to do.
- Home NodeB (HNB) – Connected to an existing residential broadband service, an HNB provides radio coverage for standard 3G handsets within a home. HNBs incorporate the capabilities of a standard NodeB as well as the radio resource management functions of a standard Radio Network Controller (RNC).
- HNB Gateway (HNB-GW): Installed within an operator’s network, the HNB Gateway aggregates traffic from a large number of HNBs back into an existing core service network through the standard Iu-cs and Iu-ps interfaces.
- Iu-h Interface: Residing between an HNB and an HNB-GW, the Iu-h interface includes a new HNB application protocol (HNBAP) for enabling highly-scalable, ad-hoc HNB deployment. The interface also introduces an efficient, scalable method for transporting Iu control signaling over the Internet.
With an agreement on an underlying femtocell architecture, 3GPP has now transitioned to the phase of developing detailed specifications. This work is targeted for completion by the end of 2008.
- 3GPP Picks Femtocell Standard - Unstrung
- The 3GPP Home Node-B (HNB) Standard FOR FEMTOCELLS - Kineto
- 3GPP TR 25.820 - 3GPP
- 3GPP workshop on Home Node B's in, Jeju, Nov. 2007
Wednesday 28 May 2008
E-MBMS out of Rel-8, CBS in
Tuesday 29 April 2008
HSPA+ in Release-7 and Release-8
Thought of adding this while I am in mode of making lists. So whats in HSPA evolution in Rel-7 and Rel-8. Lot of people are unaware that HSPA+ was big enough to finish off in Rel-7 and was definite to spill over in Rel-8
HSPA+ Features in Release 7
- Higher Order Modulation Schemes
- Advantages and weaknesses of higher order modulation
- Interference Sensitivity
- QPSK
- 16-QAM, 64-QAM)
- Consequences
- Behavior in Time Variant Mobile Radio Channels
- Behavior of a time variant mobile radio channel
- Effect of amplitude variations
- Effect of phase variations - 16-QAM for the S-CCPCH (DL)
- MBSFN only
- Interleaving
- Modulation
- Scaling factors - 64-QAM for the HS-PDSCH (DL)
- Interleaving
- Constellation Rearrangement
- Modulation
- Related UE Categories - 16-QAM for UL (4-PAM for the E-DPDCH)
- HARQ Rate Matching Stage
- Interleaver
- Modulator
- UE category - Overview Advantages and Disadvantages
- Higher peak data rate
- Better resource utilization
- Blind choice of modulation scheme
- High SNIR requirement
- More TX power requirement
- Low range
- Small cell environment
- Restrictions of use for high UE moving speeds - Channel Estimation Algorithms
- Normal Algorithm
- Gathering pilot information
- Channel estimation
- Data detection
- Advantage
- Disadvantage
- Advanced Algorithms
- Shorter channel estimation window
- Moving channel estimation window
- Adaptive detection
- Turbo detection
- Advantages
- Disadvantages - Performance16-QAM in the UL
- Performance on Link Level 16-QAM in the UL
- Performance of BPSK compared to 4-PAM
- Influence of non-linearity of the power amplifier
- Performance on System Level
- Behavior with increasing load
- Maximum versus average throughput - Higher Order Modulation Testing
- Test Setup for 16-QAM in the UL
- RF components
- Discussion of the setup
- Selected Performance Requirements for 16-QAM in the UL
- BPSK vs. 4-PAM
- Effect of RX diversity
- Effect of high degree of multipath
- Effect of high UE moving speed - MIMO
- Introduction to MIMO Technology
- The Basics: Signal Fading Physics between TX and RX
- Scattering
- Refraction
- Reflection
- Diffraction
- Multiplexing Dimensions
- The Multipath Dimension
- MIMO General Operation - MIMO Feedback Procedure (PCI)
- Motivation of Spatial Precoding
- Plain MIMO
- Multiple rank beamforming
- Spatial Precoding
- Codebook, PCI and CQI Loop
- Codebook
- PCI and CQI loop - MIMO Algorithms
- Linear MIMO Algorithms (Preparation work, Equalizer at the end of the processing chain,
- Equalizer at the beginning of the processing chain), Non-Linear MIMO Algorithms - MIMO Performance
- MIMO Performance on Link Level (SISO vs. SIMO, SIMO vs. MIMO, 2x2 MIMO vs. 4x2
- MIMO, 16-QAM vs. 64-QAM), Performance on System Level (MIMO vs. SIMO, 50% vs.
- 75% power allocation, 0% vs. 4% feedback errors) - MIMO Tests
- Official Test Setups (Test NodeB, Fading simulator, Noise generator, UE under test, Single stream test setup, Double stream test setup), Quick and Easy Test Setups (The
easiest test setup, A more reliable test setup: The MIMO circle), Selected Performance
- Requirement Figures (Conditions, 64-QAM performance, Dual stream MIMO
performance, Single stream MIMO performance) - Continuous Packet Connectivity (CPC)
- Basic features
- Uplink Discontinuous Transmission (DTX), Downlink Discontinuous Reception (DRX) - RRC message ID’s
- DTX and DRX Information - CPC Timing
- Uplink CQI transmission - Example for Uplink DPCCH Burst Pattern for 10 ms E-DCH TTI
- Uplink DRX, Downlink DRX - Uplink DPCCH preamble and postamble
- Uplink DPCCH preamble and postamble for the DPCCH only transmission, Uplink DPCCH preamble and postamble for the E-DCH transmission, Uplink DPCCH preamble and postamble for the HS-DPCCH transmission - Example of simultaneous Uplink DTX and Downlink DRX
- CPC and Enhanced F-DPCH
- Timing Implications for CPC + Enhanced F-DPCCH - Upgraded L1 Signaling
- HS-SCCH Review of Rel. 5 and 6
- HS-SCCH Frame Structure, HS-SCCH Part 1 and 2 Forward Error Coding Chain, UE
specific masking of Part 1 and Part 2, HS-PDSCH Code Allocation through Part1 of HSSCCH,
- Transport Block Size Determination – TFRI Mapping - HS-SCCH of Rel. 7
- HS-SCCH Overview of Rel. 7 (HS-SCCH type 1, No HS-SCCH, HS-SCCH type 2, HSSCCH
type 3), HS-SCCH Type 1 (HS-SCCH Type 1, HS-SCCH Type 1 for Configured 64-QAM Operation, HS-SCCH Orders, 64-QAM Constellation Versions), HS-SCCH Type 2 (for HS-SCCH less operation) (Use of the HS-SCCH-less operation, Procedure HSSCCH-less operation), HS-SCCH Type 3 (HS-SCCH Type 3 Overview, Modulation and
Transport Block Number , HARQ Process Number, Redundancy Version and
Constellation Version) - HS-DPCCH of Rel. 7
- HS-DPCCH ACK/NACK (ACK-NACK of primary TB in R5, Preamble and postamble in
R6, ACK-NACK of 2 TB’s in R7), HS-DPCCH PCI and CQI type A and B (CQI in case of
no MIMO operation, PCI and CQI in case of MIMO with 1 TB (CQI type A), PCI and CQI
in case of MIMO with 2 TB’s (CQI type B)) - E-AGCH and E-DPCCH
- Changes in the E-TFCI tables, Changes in the AG tables, Changes in the SG tables - MAC-ehs Entity versus MAC-hs
- UTRAN side MAC-hs Details – CELL_DCH only
- Flow Control, Scheduling/Priority Handling, HARQ, TFRC selection - UE side MAC-hs Details – CELL_DCH only
- HARQ, Reordering Queue distribution, Reordering, Disassembly - UTRAN side MAC-ehs Details
- Some advantages of MAC-ehs compared to MAC-hs , Flow Control, HARQ, TFRC
selection (~ TFRI), LCH-ID mux, Segmentation - UE side MAC-ehs Details
- HARQ , Disassembly, Reordering queue distribution, Reordering, Reassembly, LCH-ID demultiplexing - Differences in the MAC-ehs and MAC-hs Header
- MAC-hs Header Parameter Description
- MAC-hs SDU , , MAC-hs Header of MAC-hs PDU), MAC-ehs Header Parameter Description
- MAC-ehs Header Parameter Details
- HARQ Process Work Flow in UE – MAC-hs / MAC-ehs
- Split HS-DSCH Block Functionality
- Practical Exercise: MAC-hs contra MAC-ehs
- MAC-hs / MAC-ehs Stall Avoidance
- Timer-Based Scheme
- Window Bases Scheme
- MAC-(e)hs Reordering Functionality – Timer / Window based - Flexible RLC PDU Sizes
- The RLC AMD PDU – Rel. 7 Enhancements
- The Poll (POLL) super-field
- RLC AMD Header Fields
- Release 7 Enhancement of the HE-Field and LI - Comparison of RLC-AM between Rel. 6 and Rel. 7
- RLC-AM Overhead using fixed or flexible PDU size
· RRC State Operation Enhancements - Transport Channel Type Switching with HSPA in R6
- Transport Channel Combinations between UL and DL, Radio Bearer Multiplexing Options in Rel. 6 - Operation of UTRA RRC States in Release 7
- UE Idle mode, CELL_DCH state - HS-DSCH Reception in CELL_FACH and XXX_PCH
- Overview (UE dedicated paging in CELL_DCH, CELL_FACH and CELL_PCH, BCCH
reception in CELL_FACH, FACH measurement occasion calculation, Measurement
reporting procedure), (1) Operation in the CELL_FACH state (DCCH / DTCH reception in
CELL_FACH state , User data on HS-DSCH in Enhanced CELL_FACH state), (2) Operation in the CELL_FACH state – Cell Update, (3) RRC Idle to transient CELL_FACH
(Common H-RNTI selection in CELL_FACH (FDD only), H-RNTI selection when entering
Connected mode (FDD only) ), Operation in the URA_PCH or CELL_PCH state (Data
Transfer in CELL_PCH with dH-RNTI, State Transision from CELL_PCH to CELL_FACH
to CELL_DCH, CELL_PCH and URA_PCH enhanced Paging Procedure)
HSPA+ Features in Release 8
- Overview of HSPA+ Related Work Items in R8
- Requirements for two branch IC
- CS voice over HSPA
- Performance req. for 15 HSDPA codes
- MIMO + 64-QAM
- Enhanced DRX
- Improved L2 for UL
- Enhanced UL for CELL_FACH
- R3 Enhancements for HSPA
- Enhanced SRNS relocation
- MIMO combined with 64-QAM
- New UE Categories
- Data Rate, Soft IR memory - L1 Signaling of MIMO and 64-QAM
- Modulation Schemes and TB Sizes (Signaling on the HS-SCCH type 3, Dilemma to signal
on the modulation schema and TB number field, Solution), CQI Signaling, CQI Tables
used
Interested readers can refer to Alcatel-Lucent presentation in HSPA+ Summit here.
There is also an interesting Qualcomm paper titled, "Release 7 HSPA+ For Mobile Broadband Evolution" available here.
3GPP Release 8 Features
- Maintenance of TISPAN documentation
- FS on 3G Home NodeB
- FS on Multimedia Session Continuity
- FS on CS Domain Services over evolved PS access
- FS on Transferring of emergency call data – in-band modem solution
- FS on Improved network controlled mobility between LTE and 3GPP2/mobile WiMAX radio technologies
- FS on IMS Application Server Service Data Descriptions for AS interoperability
- FS Restoration Procedures
- Registration in Densely-populated area
- Lawful Interception in the 3GPP Rel-8
- IMS Enhancements for support of Packet Cable access
- Study on Non 3GPP access NSP
- Support of Service-Level Interworking for Messaging Services
- Feasibility Study of Mobility between 3GPP-WLAN Interworking and 3GPP Systems
- Study on Requirements for seamless roaming and service continuity between mobile and WLAN networks
- Study on Stage 2 aspects of IMS Service Brokering
- Study of Requirements of IP-Multimedia Subsystem (IMS) Convergent Multimedia Conferencing
- Study on support of a Public Warning System (PWS)
- Study of VCC support for Emergency Calls
- Study on centralized IMS services
- Study on centralised IMS service control
- Consumer protection against spam and malware
- 3G Long Term Evolution
- GERAN support for GERAN - 3G Long Term Evolution interworking
- Local Charging Zone Requirements
- Enhancements to BS30 Bearer service for Videotelephony
- IMS Enhancements Rel-8
- NDS Authentication Framework Extension for TLS
- Study on Value Added Services for Short Message Service
- Value Added Services for Short Message Service
- Study on Paging Permission with Access Control (PPAC)
- Paging Permission with Access Control
- GAN Enhancements
- Earthquake and Tsunami Warning System
- FS on Extended Support of IMS Emergency Calls
- Study on System enhancements for the use of IMS services in local breakout
- Study on Services Alignment and Migration
- Study on A-interface over IP
- Study on Multi-User Reusing-One-Slot
- Study on Optimized Transmit Pulse Shape for Downlink EGPRS2-B
- Study on InterWorking Function between MAP based and Diameter based interfaces
- Study on Evaluation of the inclusion of Path Loss Based Technology in the UTRAN
- LCS for 3GPP Interworking WLAN
- All-IP Network (AIPN)
- 3GPP System Architecture Evolution Specification
- CT aspects of System Architecture Evolution
- FBI Phase 2
- Rel-8 Feasibility Studies
- IMS Centralised Service Control
- IMS Multimedia Telephony and Supplementary Services
- MTSI Video - Dynamic Rate Adaptation/Signalling of Image Size
- eCall data transfer Phase 2: Comparison of alternative in-band modem solutions and standardization of one in-band modem solution
- Requirements and Test methods for Wideband Terminals
- Extending PSS and MBMS User Services for optimized Mobile TV
- IMS initiated and controlled PSS and MBMS User Service
- Storage and easy access of ICE numbers on USIM
- IP Interconnection of Services
- Network Selection for non-3GPP Access
- Charging for multi-phases services
- Home NodeB / eNodeB
- 3GPP2 Input to Common IMS
- Rel-8 Improvements of the Radio Interface
- OAM&P 8
- OAM&P Rel-8 Studies
- Study of Element Operations Systems Function (EOSF) definition
- Study on SA5 MTOSI XML Harmonization
- Study of Common Profile Storage (CPS) Framework of User Data for network services and management
- Study of Management for LTE and SAE
- Study on Charging Aspects of 3GPP System Evolution
- Study of System Maintenance by Itf-N
- Study of Self-Organizing Networks (SON) related OAM interfaces for Home NodeB
- Study on Self-healing of Self-Organizing Networks (SON)
- Personal Network Management (PNM)
- eCall Data Transfer – Requirements
- IMS System enhancements for corporate network access
- IMS Service Brokering enhancements
- Network Composition
- FS on Scope of future HSPA Evolution for 1.28Mcps TDD
- FS on Synchronised E-DCH for UTRA FDD
- Study on Dual-Cell HSDPA operation
- (FS on) Service continuity between mobile and WLAN networks
- I-WLAN NSP
- Interworking Wireless LAN Mobility
- Multimedia Priority Service
- Multimedia interworking between IMS and CS networks
- Conferencing enhancements for Mp interface
- Enhancements for VGCS Applications
- Contact Manager for 3GPP UICC applications (formerly ""Enhanced USIM Phonebook"")
- Charging Management small Enhancements
- Harmonization of Gq'/Rx for Common IMS
- IMS Service Continuity
- Interworking between User-to-User Signaling (UUS) and SIP
- Support of Overlap signalling
- OSA Rel-8
- Rel-8 RAN improvements
- Combination of 64QAM and MIMO for HSDPA (FDD)
- Security Enhancements for IMS
- Generic Bootstrapping Architecture Push Function
- Support of (G)MSC-S – (G)MSC-S Nc Interface based on the SIP-I protocol
- IMS Stage-3 IETF Protocol Alignment
- New multicarrier BTS class
- Support of Customised Alerting Tone Service
- Facilitating Machine to Machine Communication in GSM and UMTS (M2M)
- SI on AS-MRFC media server control protocol
- AS/MRFC stage 2 and 3 work
- (Small) Technical Enhancements and Improvements for Rel-8
Monday 16 July 2007
300 Mbps with 'Super-FOMA'
Friday 6 July 2007
3GPP Release 8 = 3GPP IMS + ETSI TISPAN
In cooperation with the European Telecommunications Standards Institute, the 3rd Generation Partnership Project (3GPP) has re-chartered a services group tasked with common ETSI-3GPP development of IP Multimedia Subsystem (IMS) Version 8.
Both standards bodies hailed the early June agreement, reached during a meeting in Busan, Korea, as an effective way to keep 3GPP IMS and ETSI Telecoms & Internet converged Services & Protocols for Advanced Networks (TISPAN) work.
Both IMS and TISPAN comprise next-generation network standards efforts designed to forge a higher signaling and control plane infrastructure layer to support delivery of content and applications to subscribers across any fixed or mobile network or device.
Common IMS developments will form part of 3GPP Release 8, which is expected to be functionally frozen by end 2007.
“Over the next few months we must stabilize the Release 8 requirements and absorb the incoming Common IMS work,” Stephen Hayes, Ericsson Inc., 3GPP TSG-SA Chair Stephen Hayes of Ericsson Inc., said. “3GPP has a history of successfully meeting challenges and I have no doubt we will meet these challenges as well.”
Thursday 24 May 2007
Almost 300,000 LTE Base Transceiver Stations by 2014
LTE brings to the market 25 years of operating experience using TDM and CDMA technology. It aims to use that, combined with OFDM, and other techniques, to provide the best of both worlds, perhaps stealing WiMAX’s thunder. This also takes the industry from the current two-network approach of circuit switching for voice, and packet switching for data to a single IP network for both services.
“LTE faces competition from other broadband wireless technologies and it will need to demonstrate clear technical and economic advantages to convince network operators,” says ABI Research analyst Ian Cox. “The mobile variant of WiMAX will start to appear in 2007 as the WiMAX Forum Certification program ramps up. The industry is also working on HSPA+, which could offer the same performance in a 5 MHz bandwidth. Without additional spectrum, operators could face a difficult choice.”
Cox further comments that, “LTE is the NGN for the mobile industry and is being standardized by 3GPP with the full support of operators via the NGMN Group.”
Long Term Evolution (LTE) of 3G technologies is about to benefit from Release-8 of the 3GPP standard, planned for the third quarter of 2007. The potential rewards of LTE are simplicity of operation, a “flat” architecture offering low latency, and spectrum flexibility. Backwards compatibility and roaming with 2G and 3G networks are added bonuses, along with lower power consumption and improved performance, . LTE could also unite the W-CDMA and CDMA communities because of its spectral flexibility.
For vendors, LTE will allow development of a new market to replace declining 3G revenues.
For users, says Cox, LTE will enable broadband services, including VoIP, to be offered over SIP-enabled networks. Each service will be IP-based, offering high data rates and low latency, with on-line gaming becoming a reality along with mobile network data speeds comparable to those of fixed networks.
“UMTS Long Term Evolution”
(http://www.abiresearch.com/products/market_research/UMTS_Long_Term_Evolution) reviews the world market for LTE.
Tuesday 22 May 2007
LTE in few words
3G LTE, as proposed in 3GPP Release 8, aims to increase cell data capacity by at least five times over the current implementations of HSPA. It will support more users per cell, as well as higher speeds to individual users, and is intended to match DSL speeds currently available to the home. A simplified protocol structure and re-definition of the functional split between network elements and basestations is intended to raise efficiency while making all VoIP networks possible.
Some of the highlights of LTE are:
- OFDM-based air interface (Orthogonal Frequency Division Multiplexing) ... WCDMA is out.
- Channel bandwidths from 1.25 to 20MHz are supported
- Increased spectrum efficiency and peak data rates at cell edge.
- Target peak rates of 100 Mbps/DL and 50 Mbps/UL. (Nokia-Siemens have already achieved 108Mbps though)
- Increased spectrum efficiency and peak data rates at cell edge.
- Reduced latency for both user and control plane: less than 10ms round trip delay for user plane between UE and the serving RAN node, less than 100ms transition time for control plane between inactive state and active state.
- Support for diversity and MIMO
The first LTE-based networks are expected to roll out in 2009/2010. In contrast to other cellular technologies, conformance tests for LTE are expected to be available more than two years ahead of any service introduction according to Agilent. This will ensure user devices are available in volume when the network services are finally launched.