3GPP - 4G Americas

1 INTRODUCTION
Demand for wireless data services is growing faster than ever before. While demand for
applications such as text messaging (SMS), Web and WAP access, Multimedia Messaging
(MMS) and content downloads has kick-started the wireless data market, the demand for higher
bandwidth video applications such as video sharing, mobile video and IPTV is quickly growing.
Most UMTS/HSPA operators today are offering some type of mobile broadband service and
many PC vendors offer notebooks with built-in HSDPA capabilities that will boost data usage
even further. Clearly, data revenues are playing an increasingly important role for operators,
driving the need for higher bit rates, lower latency and more spectrally efficient support of data
services.
There was significant growth in HSDPA and HSUPA deployments in 2008. The combination of
HSDPA and HSUPA, called HSPA, provides a very spectrally efficient wireless solution which
many operators have now commercially deployed, leading the operators to begin focusing on
enhancements to HSPA through 3GPP Rel-7. The evolution to 3GPP Rel-7 will bring improved
support and performance for real-time conversational and interactive services such as Push-totalk
Over Cellular (PoC), picture and video sharing, and Voice and Video over IP through the
introduction of features like MIMO (Multiple Input Multiple Output antennaes), Continuous Packet
Connectivity (CPC) and Higher Order Modulations (HOMs). These Rel-7 enhancements are
often called Evolved HSPA or HSPA+. Since the Evolved HSPA enhancements are fully
backwards compatible with Rel-99/Rel-5/Rel-6, the evolution to Evolved HSPA has been made
smooth and simple for operators.
3GPP is now nearing completion of the Rel-8 specification (targeted for March 2009) which, in
addition to further enhancements of the HSPA technology, defines a new OFDMA-based
technology through the Long Term Evolution (LTE) work item. This new OFDMA-based airinterface
is also often referred to as the Evolved UMTS Terrestrial Radio Access (EUTRA). Rel-
8 also defines a new flatter-IP core network to support the EUTRAN through the System
Architecture Evolution (SAE) work item, which has recently been renamed the Evolved Packet
Core (EPC) Architecture (Note: the complete packet system consisting of the EUTRAN and the
EPC is called the Evolved Packet System (EPS)). In this paper, the terms LTE and EUTRAN will
both be used to refer to the evolved air-interface and radio access network based on OFDMA,
while the terms SAE and EPC will both be used to refer to the evolved flatter-IP core network.
Additionally, at times EPS will be used when referring to the overall system architecture. The
combination of LTE and SAE provides the long-term vision for 3GPP to an all-IP, packet-only
wideband OFDMA system expected to further improve performance by providing higher data
rates, improved spectral efficiency and reduced latency. The ability of LTE to support
bandwidths wider than 5 MHz is of particular importance as the demand for higher wireless data
speeds and spectral efficiencies continues to grow. Note that although the completion of Rel-8 is
targeted for March 2009, the Layer 1 specifications for Rel-8 have been mostly complete since
September 2008, so many of the long lead items for development have been stable for awhile at
this point.
With the completion of Rel-8 nearing, planning has already begun with 3GPP for Rel-9 and Rel-
10. There is an aggressive target schedule for Rel-9 (to complete in one year by March 2010),
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