Comparing Mobile WiMAX to 1*EVDO and HSPA in 3G..

Evolution Data-Optimized (1*EVDO) and High-Speed Downlink Packet Access (HSDPA/HSPA) have evolved from 3G CDMA standards to provide data services over a network originally conceived for mobile voice services. These 3G enhancements have evolved from the 3G experiences and as a result, inherit both the advantages and limitations of legacy 3G systems. WiMAX on the other hand was initially developed for fixed broadband wireless access and is optimized for broadband data services. Since Mobile WiMAX has evolved from systme concepts initially designed for fixed wireless access, WiMAX faces the challenge of meeting the additional requirements necessary to support mobility. A point by point comparison of the attributes of Mobile WiMAX with 3G-based 1*EVDO and HSDPA/HSPA systems is useful in addressing how these technologies can meet future network requirements for mobile broadband data services.

• Common features

Several features, designed to enhance data throughput, are common to EVDO, HSDPA/HSPA and Mobile WiMAX including:

- Adaptive modulation and coding (AMC)

- Hybrid ARQ (HARQ)

- Fast schedulig

- Bandwidth efficient handoff

• Key advantages of Mobile WiMAX

Unlike the CDMA-based 3G systems, which have evolved from voice-centric systems, WiMAX was designed to meet the requirements necessary for the delivery of broadband data services as well as voice. The Mobile WiMAX physical layer is based on Scalable OFDMA technology. The new technologies employed for Mobile WiMAX result in lower equipment complexity and simpler management due to the all-IP core network and provide Mobile WiMAX systems with many other CDMA-based 3G systems including:

- Tolerance to Multipath and Self-Interference

- Scalable Channel Bandwidth

- Orthogonal Uplink Multiple Access

- Support for Spectrally-Efficient TDD

- Frequency-Selective Scheduling

- Fractional Frequency Reuse

-Fine Quality of Service (QoS)

- Advanced Antenna Technology

All the systems have adopted advanced technologies to improve data throughput. However Mobile WiMAX, is based on OFDM/OFDMA technology which is more suitable for broadband wireless data communication. In fact OFDM/OFDMA is one proposal being considered in 3GPP/3GPP2 as the solution for LTE and is generally accepted as being the basis for 4G. An OFDM/OFDMA-based systme has high granular resourece allocation, better uplink efficiency, and can support a full range of advanced antenna technologies. These capabilities offer the potential for significant spectral efficiency advantages and better QoS in both the downlink and uplink direction. Mobile WiMAX can slso dynamically adjust downlink/uplink ratio with TDD support providing greater flexibility and spectral efficiency advantages in supporting varied types of broadband traffic. In contrast, EVDO and HSPA, based on FDD, have a fixed asymmetric downlink/uplink ratio determined by the difference in downlink/uplink spectral efficiency and fixed FDD channel bandwidth. Additionally, Mobile WiMAX provides superior QoS and offers operators greater flexibility in implementing Service Level Agreements to meet varied customer requirements.

From a performance perspective, only Mobile WiMAX can transport DSL and cable-like services cost-effectively in a mobile environment. This is an essential requirement for the success of Mobile WiMAX, a technology aimed at delivering broadband mobile services ranging from real-time interactive gaming, VoIP, and streaming media to non-real-time web browsing and simple file transfers.

Other benefits of WiMAX include its open standard approach and healthy ecosystem. Hundreds of companies have contributed to the development of the technology and many companies have announced product plans for this technology. The broad industry participation with worldwide adoption of th estandard will ensure economies of scale that will help drive low cost of subscription and enable the deployment of broadband mobile services in both developed and emerging markets. With a scalable architecturem high data throughput and low cost of deployment Mobile WiMAX is a leading solution for wireless broadband services. By creating a common platform that addresses a wide range of market segments, Mobile WiMAX is well-positioned to experience a high global take rate.