Release 7 HSPA+ For Mobile Broadband Evolution Qualcomm Incorporated November 2007 Release 7 HSPA+ For Mobile Broadband Evolution Table of Contents [1] Executive Summary ......................................................................... 1 [2] Introduction and Overview ............................................................... 2 2.1 What is HSPA+?...................................................................... 3 [3] HSPA+ Doubles Data Capacity and Reduces Cost ........................ 4 3.1 Multiple Input Multiple Output (MIMO)..................................... 6 3.2 Higher Order Modulation (HOM) ............................................. 7 3.3 Discontinuous Transmission (DTX) and Discontinuous Reception (DRX)..................................................................... 7 [4] HSPA+ Provides Three Times Increased Voice Capacity............... 8 [5] Higher Data Capacity through VoIP............................................... 10 [6] Enhanced User Experience Benefits ............................................. 11 [7] HSPA+ Offers an Entire Range of IP Services.............................. 12 7.1 VoIP Enables Rich Services.................................................. 13 7.2 VoIP Simplifies Fixed Mobile Convergence .......................... 14 [8] Backward Compatibility and Leverage in a Large 3G Ecosystem. 15 [9] The Optimal Solution in 5 MHz ...................................................... 16 [10] Conclusion ................................................................................... 18 11/2007 page i Release 7 HSPA+ For Mobile Broadband Evolution [1] Executive Summary UMTS operators are rapidly launching High Speed Packet Access (HSPA) services to capitalize on HSPA’s mobile broadband capabilities and increased data capacity. As the natural evolution, HSPA+ further enhances the performance and capabilities of HSPA. HSPA+ is expected to be commercially available in 2008 through incremental investments and backward and forward compatible handsets. HSPA+ doubles the data capacity and increases voice capacity by three times enabling operators to offer mobile broadband at even lower cost. Moving voice traffic to VoIP over HSPA not only increases the voice capacity in itself, it also significantly increases data capacity. While HSPA already supports the full range of packet-based IP services with integrated Quality of Service (QoS). HSPA+ further enhances the end-user experience through higher peak rates, lower latency, extended talk time and a true “always-on” experience. HSPA+ is the optimal solution for a 5 MHz carrier and provides similar data and voice capacity as LTE in the 5 MHz block for the same number of antennas. 11/2007 page 1 Release 7 HSPA+ For Mobile Broadband Evolution [2] Introduction and Overview UMTS operators are rapidly launching HSPA services to capitalize on its mobile broadband capabilities and increased data capacity. The enhanced downlink (HSDPA) had been launched commercially by 128 UMTS operators as of mid-2007, and deployment of the enhanced uplink (HSUPA) began during 2007. HSPA+, expected to be commercially available by the end of 2008, is the natural evolution of HSPA. It further enhances the performance and capabilities of HSPA. This white paper discusses these key benefits of HSPA+: HSPA+ doubles the data capacity over HSPA, thus reducing the cost of delivering data services and offering a better mobile broadband experience. HSPA+ provides three times more voice capacity through VoIP than R99 circuit-switched voice with the same quality and codec. HSPA+ VoIP frees up significant data capacity. The higher VoIP efficiency can also be used to free up significant data capacity in a mixed VoIP and data usage model. This helps to meet the increased demand for data services. HSPA+ enhances the end-user experience through higher peak rates, lower latency, faster call set-up time, significantly longer talk time and a true “always-on” experience. HSPA+ supports downlink peak rates up to 28 Mbps (42 Mbps in 3GPP Release 8) and up to 11 Mbps in the uplink. HSPA+ is the most economical evolution of HSPA, allowing UMTS operators to most efficiently use their existing assets and investments in network, spectrum and devices. Like HSPA, HSPA+ is forward and backward compatible, allowing for a phased introduction of devices and a smooth upgrade to existing nodes. HSPA+ is the optimal solution for a 5 MHz carrier, for existing, re- farmed 900 MHz, and for new spectrum; it provides similar data and voice performance as LTE in a 5 MHz block, using the same number of antennas. 11/2007 page 2 Release 7 HSPA+ For Mobile Broadband Evolution 2.1 What is HSPA+? HSPA+ is the name of the set of HSPA enhancements that are defined in 3GPP Release 7 (R7) and beyond. The enhanced downlink (HSDPA) was defined in 3GPP R5 and provides three times the data capacity of WCDMA R99 (using a rake receiver and a single UE receive antenna). Broadband Broadband Enhanced Voice downloads uploads and data capacity Rel-99 Rel-5 (HSDPA) Rel-6 (HSUPA) Rel-7 Rel-8 WCDMA HSPA HSPA+ (HSPA Evolved) DL: 384 Kbps DL: 14.4 Mbps DL: 14.4 Mbps DL: 42 Mbps UL: 384 Kbps UL: 384 Kbps UL: 5.72 Mbps UL: 11 Mbps Figure 1: UMTS Evolution The enhanced uplink (HSUPA) was defined in R6 and doubles the uplink data capacity over WCDMA R99. This paper focuses on the first step of the HSPA evolution and the enhancements that have been defined in 3GPP R7. HSPA will continue to evolve and 3GPP R8 and beyond will introduce features that will further enhance the HSPA performance. Table 1 presents the key HSPA+ R7 features and their benefits. HSPA+ Features Key Benefits DL 2x2 Multiple Input Multiple Doubles peak data rates Output (MIMO) Increases downlink capacity 50% higher downlink peak data rate Higher Order Modulation (HOM) Doubles uplink data peak rate 64-QAM DL and 16-QAM UL Increases uplink and downlink capacity Improves VoIP capacity Continuous Packet Connectivity Extends talk time by up to 50% (CPC): DTX/DRX, HS_SCCH Less Better “always-on” experience Enhanced CELL_FACH state Faster cell set up operation Better “always-on” experience MBSFN Increases broadcast capacity (single frequency network) Better broadcast cell edge rate Table 1: Key HSPA+ R7 Features 11/2007 page 3 Release 7 HSPA+ For Mobile Broadband Evolution In addition to the HSPA+ enhancements defined in the 3GPP standards, we anticipate that interference cancellation (IC), both in the uplink (Node B IC) and downlink (UE IC) will be introduced in the same timeframe as HSPA+. Thus, the performance numbers discussed in this paper assume implementation of Node B IC. While the use of 4-Branch receive diversity could further double the uplink capacity, and the use of UE IC would increase the downlink capacity and enhance user experience at the cell edge through higher rates, those enhancements are not taken into account for the performance projections in this paper. Additional HSPA+ Features Key Benefits (Expected to be available same timeframe as HSPA+ R7) Uplink Interference Cancellation Increases uplink capacity and rates (Node B IC) Beneficial for VoIP Downlink Interference Cancellation Increases Downlink capacity (UE IC) Higher Downlink cell edge data rate Increases uplink capacity (>100%) Node B four-way receive diversity Higher uplink cell edge data rates Table 2: Standard Independent HSPA+ Features [3] HSPA+ Doubles Data Capacity and Reduces Cost With the launch of HSPA, operators are seeing a significant uptake in data demand, a result of new data applications and increased demand for high-performance mobile broadband services. HSPA+ enhances the performance of HSPA networks and enables wireless operators to continue to fulfill these data needs in the most economical way, as HSPA+ doubles the data capacity compared to HSPA R6 (assuming a rake receiver and receive diversity at the HSPA R6 UE). Figure 2 compares the downlink and uplink data capacity of HSPA and HSPA+. The almost doubled downlink and uplink data capacity assumes advanced receivers (UE equalizer, UE receive diversity and Node B IC)1 in addition to the HSPA+ features. These results do not take higher order modulation (HOM) schemes into consideration (64-QAM on the downlink 1 Type 3 UE receiver: linear MMSE equalizer and receive diversity. 11/2007 page 4 Release 7 HSPA+ For Mobile Broadband Evolution and 16-QAM in the uplink). It is expected that HOM will provide further performance boost in particular deployment scenarios. HSPA greatly increased data capacity over R99 systems by adding the high-speed shared channels with HOM (16-QAM), smaller transmission interval, Hybrid ARQ and opportunistic scheduling. HSPA+ builds on this solid foundation by adding support for 64-QAM, 2x2 MIMO, CPC and other air interface improvements. Additional enhancements are being planned for R8 and beyond, which will provide a clear evolution path for current networks. Some of the HSPA+ enhancements that improve data capacity are discussed below. Data Capacity Per Sector Mbps (5MHz) 7.81 6.18 2.3X 1.8X 3.44 Downlink 1X R6 HSPA baseline R6 HSPA R7 HSPA+ (RxDiv) (RxDiv+EQ) (2x2 MIMO) 2.61 1.7X 1.55 1X Uplink R6 HSPA R7 HSPA Baseline (RxDiv+IC) Source: Qualcomm Simulations, 500m ISD, 64-QAM in DL not considered, 16-QAM in UL not considered. Details in 3GPP R1-070674. Figure 2: Data Capacity per Sector in Mbps (5 MHz) 11/2007 page 5 Release 7 HSPA+ For Mobile Broadband Evolution 3.1 Multiple Input Multiple Output (MIMO) HSPA+ supports 2x2 downlink MIMO that uses two transmit antennas at the Node B to transmit