Process and Requirements for IMT-Advanced Miia Mustonen VTT Technical Research Centre of Finland Slide 1
Outline Definitions Process and time schedule of IMT-Advanced Minimum requirements Technical Performance Spectrum Services Evaluation guidelines Evaluation methods Candidate RITs Slide 2
Definitions International Telecommunication Union (ITU) is an international organization within United Nations where governments and the private sector coordinate global l telecommunication networks and services. It is the only body which is responsible for recommending standards for International Mobile High Medium Mobility IMT- 2000 Enhancement Enhanced IMT-2000 IMT-2000 Telecommunication (IMT) systems. ITU-R WP 5D is responsible for IMT Systems Low New Mobile Access IMT IMT- ADVANCED New Nomadic / Local Area Wireless Access 1 10 100 1000 Communication speed / Carrier bitrate (Mbit/s) IMT-2000 encompasses all 3G mobile communication standards d and their enhancements Slide 3
Definitions IMT-Advanced is the ITU name for systems beyond IMT-2000 i.e., 4G systems A mobile system that t includes the new capabilities of IMT Provides access to a wide range of telecommunication services supported by mobile and fixed networks Supports low to high mobility applications and a wide range of data rates according to user and service demands in multiple environments. Key Features of IMT-Advanced [M.1822] A high degree of commonality of functionality worldwide while flexibility to support a wide range of services and applications cost efficiently. Compatibility of services within IMT and with fixed networks. Capability of interworking with other radio access systems. High quality mobile services. User equipment suitable for worldwide use. User-friendly applications, services and equipment. Worldwide roaming capability. Enhanced peak data rates to support advanced services and applications. Slide 4
Definition of Candidate RIT/SRIT A Radio Interface Technology (RIT) can enter the process to become an IMT-Advanced technology if it fulfils the minimum requirements for at least one test environment (indoor, microcellular, base coverage urban and high speed). However, an RIT cannot be accepted as an IMT-Advanced technology unless it fulfils the minimum requirements in at least three of the test environments. If an RIT enters the process not fulfilling the requirements in three of the test environments it can form a set of RITs (SRITs) with other RITs each individually fulfilling the minimum requirements for at least one test environment and complementing each other. Slide 5
Definition of Circular Letter The purpose of the Circular Letter (CL) for IMT-Advanced is to invite the ITU-R members and other organizations to submit proposals for candidate Radio Interface Technologies or a set of RITs for terrestrial component of IMT-Advanced, to initiate the ongoing process to evaluate candidate RITs or SRITs for IMT-Advanced, to invite the formation of independent evaluation groups and subsequent submission of evaluation reports Slide 6
Process and time schedule of IMT-Advanced Slide 7
Minimum requirements Cell spectral efficiency Cell spectral efficiency (η) is defined as the aggregate throughput of all users (the number of correctly received bits by user i (downlink) or from user i (uplink) χ i delivered d to Layer 3, over a certain period of time T) divided by the channel bandwidth ω and the number of cells M. Thus, N χ Test environment i = 1 η = T ω M Downlink (bit/s/hz/cell) i Uplink (bit/s/hz/cell) Indoor 3 2.25 Microcellular 2.6 1.8 Base coverage urban 22 2.2 14 1.4 High speed 1.1 0.7 These values have been defined assuming an antenna configuration of downlink 4x2, uplink 2x4 Slide 8
Minimum requirements Peak Spectral Efficiency The peak spectral efficiency is the highest theoretical data rate (normalized by bandwidth), assuming error-free conditions assignable to a single mobile station, when all available radio resources for the corresponding link direction are utilized. The minimum requirements for peak spectral efficiencies are 15 bit/s/hz for downlink and 6.75 bit/s/hz for uplink*. Examples: Downlink peak data rate in 40 MHz is 600 Mbit/s and in 100 MHz is 1 500 Mbit/s. Uplink peak data rate in 40 MHz is 270 Mbit/s and in 100 MHz is 675 Mbit/s. *These values have been defined assuming an antenna configuration of downlink 4x4, uplink 2x4 Slide 9
Minimum requirements Cell edge user spectral efficiency The cell edge user spectral efficiency is defined as 5% point of the cumulative distribution function (CDF) of the normalized user throughput. The normalized user throughput of user i, γ i, is defined as χi γ i = Ti ω where χ i denotes the number of correctly received bits of user i, T i the active session time for user i and ω the channel bandwidth. Test environment Downlink (bit/s/hz) Uplink (bit/s/hz) Indoor 0.1 0.07 Microcellular 0.075075 0.0505 Base coverage urban 0.06 0.03 High speed 0.04 0.015 These values have been defined assuming an antenna configuration of downlink 4x2, uplink 2x4 Slide 10
Minimum requirements Latency Control plane (C-Plane) latency Typically y measured as the transition time from different connection modes. IMT-Advanced systems shall be able to achieve a transition time of less than 100 ms from idle state to an active state in such a way that the user plane is established. User Plane Latency (transport delay) Defined as the one-way transit time between a packet being available at the IP layer in the user terminal/base station and the availability of this packet at IP layer in the base station/user terminal. IMT-Advanced systems shall be able to achieve a user plane latency of less than 10 ms in unloaded conditions for small IP packets for both downlink and uplink. Slide 11
Minimum requirements Mobility The following mobility classes are defined: stationary (0 km/h), pedestrian(0 km/h-10 km/h), vehicular(10-120 km/h) and high speed vehicular (120-350 km/h) The mobility classes to be supported by IMT-Advanced system are listed in the table together with the traffic channel link data rate (normalized by bandwidth) that needs to be supported on the uplink when the user is moving at the maximum speed in that environment. Mobility classes supported Traffic channel link data rates* [bits/s/hz] Indoor Microcellular Base coverage urban Stationary, pedestrian Stationary, pedestrian, Vehicular (up to 30 km/h) Stationary, pedestrian, vehicular High speed High speed vehicular, vehicular 1.0 0.75 0.55 0.25 *These values have been defined assuming an antenna configuration of downlink 4x2, uplink 2x4 Slide 12
Minimum requirements Handover The handover interruption time is defined as the time duration during which a user terminal cannot exchange user plane packets with any base station. The IMT- Advanced system needs to support following handover interruption times Handover type Interruption time (ms) Intra-frequency 27.5 Inter-frequency within a spectrum band 40 between spectrum bands 60 In addition, inter-system handovers between the candidate IMT-Advanced system and at least one IMT system shall be supported, but are not subject to handover interruption time limits. Slide 13
Minimum requirements VoIP Capacity The VoIP capacity is the minimum of the calculated capacity for either link direction divided by the effective bandwidth (operating bandwidth normalized appropriately considering the uplink/downlink ratio) in the respective link direction. Test environment Min VoIP capacity (Active users/sector/mhz) Indoor 50 Microcellular 40 Base coverage urban 40 High speed 30 The values have been defined assuming an antenna configuration of 4x2 in the downlink and 2x4 in the uplink and a 12.2 kbit/s codec with a 50% activity factor such that the percentage of users in outage is less than 2%. A voice outage is experienced if less than 98% of the VoIP packets have been delivered successfully to the user within a one way radio access delay bound of 50 ms. Slide 14
Minimum requirements Bandwidth The RIT has to support a scalable bandwidth up to and including 40 MHz. This may be supported by single or multiple RF carriers. Scalable bandwidth is the ability of the candidate RIT to operate with different bandwidth allocations. It is required that the RIT supports at least three bandwidth values. Proponents are encouraged to consider extensions to support operation in wider bandwidths (e.g. up to 100 MHz) and the research targets expressed in Recommendation ITU-R M.1645 Slide 15
Minimum requirements WINNER+ Spectrum The following frequency bands have been identified for IMT and/or IMT-2000 by WARC-92, WRC-2000 and WRC-07(the identification varies between different ITU regions and even within a region in some cases): 450-470 MHz 698-960 MHz 1 710-2 025 MHz 2 110-2 200 MHz 2 300-2 400 MHz 2 500-2 690 MHz 3 400-3 600 MHz IMT-Advanced system needs to be able to utilize at least one band identified for IMT. Slide 16
Minimum requirements WINNER+ Services An IMT-Advanced system has to support wide range of services. It has been defined that if the candidate RIT fulfills requirements on peak spectral efficiency, bandwidth and latency it also fulfills the requirement on wide range of services. The support of the service classes is further analyzed by inspection in at least one test environment User Experience Class Conversational Interactive Streaming Background Service Class Basic conversational service Rich conversational service Conversational low delay Interactive high delay Interactive low delay Streaming Live Streaming Non-Live Background Slide 17
Evaluation guidelines Evaluation assessment methods Simulation (including( system and link-level simulation) ) Analytical (calculation based on technical information of the proposal) Inspection (based on statements in the proposal) Options for evaluation groups Self-evaluation must tbe a complete evaluation External evaluation group complete or partial evaluation one or several technology proposals use their simulation tools for the evaluation WINNER+ has been accepted as an External Evaluation Group for the IMT-Advanced process in ITU-R Slide 18
Evaluation methods Minimum Requirement Method for evaluation Cell spectral efficiency Simulation (system level) Peak spectral efficiency Bandwidth Cell edge user spectral efficiency Control plane latency Analytical Inspection Simulation (system level) Analytical User plane latency Analytical l Mobility Simulation (system and link level) Intra- and inter-frequency handover interruption time Analytical Inter-system handover VoIP Capacity Deployment possible in at least one of the identified IMT bands Channel bandwidth scalability Inspection Simulation (system level) Inspection Inspection Support for a wide range of services Inspection Slide 19
Candidate RITs 3GPP: An evolution of LTE (LTE Advanced) IEEE Project 802.16m: An evolution of the IEEE 802.16 WirelessMAN-OFDMA specification (OFDMA TDD WMAN developed by WiMAX Forum) 3GPP2: Not yet achieved consensus on which system the IMT- Advanced system will be based on (cdma2000, HRPD or UMB enhancement or new technology framework) ARIB (Japan): Radio Interface Technology Group will develop one or more Japanese draft proposal(s) for IMT-Advanced which will be submitted to ITU-R through Japan s national process. TTA (Korea): will submit a proposal p which will be based on 3GPPs For further information on these candidate RITs, see introduction of the technologies from http://groups.itu.int/default.aspx?tabid=383 Slide 20
Related ITU-R Reports and Recommendations ITU-R Recommendation M.1645 (2003) "Framework and overall objectives of the future development of IMT-2000 and systems beyond IMT-2000" ITU-R Recommendation M.1768 (2006) "Methodology for calculation of spectrum requirements for the future development of the terrestrial component of IMT-2000 and systems beyond IMT-2000" ITU-R Recommendation M.1822 (2007) "Framework for services supported by IMT" ITU-R Report M.2072 (2005) "World mobile telecommunication market forecast" ITU-R Report M.2074 (2005) "Radio aspects for the terrestrial component of IMT-2000 and systems beyond IMT-2000" ITU-R Report M.2078 (2006) "Estimated spectrum bandwidth requirements for the future development of IMT-2000 and IMT-Advanced" ITU-R Report M.2079 (2006) "Technical and operational information for identifying Spectrum for the terrestrial component of future development of IMT-2000 and IMT-Advanced" Takagi H. and Walke B. H. (Eds.), Spectrum Requirement Planning in Wireless Communications: Model and Methodology for IMT-Advanced. John Wiley & Sons, 2008. 248 p. Slide 21
Thank you! Questions? Miia.Mustonen@vtt.fiMustonen@vtt For further information visit a Web page for IMT-Advanced http://www.itu.int/itu-r/go/rsg5-imt-advanced/ Slide 22