A Comparison of Two Fourth Generation Technologies: WiMAX and 3GPP-LTE Jacob Scheim December 2006

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A Comparison of Two Fourth Generation Technologies: WiMAX and 3GPP-LTE - 2 -

1 Introduction

Modern wireless wide area networks (WWAN) and wireless metropolitan area networks (MAN) are under extensive investigation in recent years with a view to progressing towards 4th generation (4G) public wireless networks. The intensive standardization activity, currently in its final stages, may be considered as a major step towards 4G. One well known example of this standardization effort is the IEEE 802.16e–2005 standard for fixed and mobile broadband wireless access (Mobile WiMAX). Early systems based on this standard are expected to be deployed starting from 2007. A parallel standardization effort is the evolved UMTS terrestrial radio access network (E-UTRAN) — also known as 3GPP Long Term Evolution (3GPP-LTE) — launched by the 3rd generation standardization body (3GPP). This standardization activity has recently moved on to a working item phase and is expected to conclude during 2007. Similar to the IEEE 802.16e-2005 standard, 3GPP-LTE radio access is expected to be based on OFDMA. These standards provide the foundation for constructing networks for mobile broadband wireless access and therefore are considered as precursors to 4G. In addition, there are also other OFDM/A based research activities, non-3GPP or WiMAX related, that are targeting 4th generation wireless access networks.

2 Comparison

Table 1 below presents the key elements of a comparison between the Mobile WiMAX and 3GPP-LTE standards as they converge to 4G broadband wireless access systems. This comparison focuses mainly on the physical layer aspects of the radio access technology of these two standards.

Table 1. Comparison of 3GPP-LTE and IEEE 802.16e

Aspect Mobile WiMAX (IEEE802.16e-2005)

3GPP-LTE (E-UTRAN)

Core network WiMAX Forum™ All-IP network UTRAN moving towards All-IP

Evolved UTRA CN with IMS

Access technology: Downlink (DL) Uplink (UL)

OFDMA OFDMA

OFDMA SC-FDMA

Frequency band 2.3-2.4GHz, 2.496-2.69GHz, 3.3-3.8GHz

Existing and new frequency bands (~2GHz)

Bit-rate/Site: DL UL

75Mbps (MIMO 2TX 2RX) 25Mbps

100Mbps (MIMO 2TX 2RX) 50Mbps

Channel bandwidth 5, 8.75, 10MHz 1.25-20MHz

Cell radius 2-7Km 5Km

Cell capacity 100-200 users >200 users @ 5MHz >400 users for larger BW

Spectral efficiency 3.75[bits/sec/Hz] 5[bits/sec/Hz]

A Comparison of Two Fourth Generation Technologies: WiMAX and 3GPP-LTE - 3 -

Aspect Mobile WiMAX (IEEE802.16e-2005)

3GPP-LTE (E-UTRAN)

Mobility:

Speed

Handovers

Up to 120Km/H

Optimized hard handovers supported

Up to 250Km/H

Inter-cell soft handovers supported

Legacy IEEE802.16a through 16d GSM/GPRS/EGPRS/UMTS/HSPA

MIMO: DL UL No. of code words

2Tx X 2Rx 1Tx X NRx (Collaborative SM) 1

2Tx X 2Rx 2Tx X 2Rx 2

Standardization coverage

IEEE 802.16e-2005 PHY and MAC CN standardization in WiMAX forum™

RAN (PHY+MAC) + CN

Roaming framework New (work in process in WiMAX Forum™)

Auto through existing GSM/UMTS

Schedule forecast:

Standard completed

Initial Deployment

Mass market

2005 2007 through 2008

2009

2007

2010

2012

3 Conclusion

The parameters presented in Table 1 show that the Mobile WiMAX and 3GPP-LTE standards are technically similar. However, in terms of market perspective the two standards differ in terms of expected time to market and legacy. Although currently less mature and widespread, Mobile WiMAX appears as if it will be first to market. Significantly, WiMAX is already being tested (e.g., in Korea), whereas LTE has not yet been standardized. Following this observation, we may conclude that due to timeline benefits new service providers as well as existing cable and DSL providers wishing to offer mobile services are likely to select Mobile WiMAX as their technology for mobile broadband access. We may also conclude that in the developed world major UMTS/HSPA service providers will naturally evolve to 3GPP-LTE, whereas most CDMA2000 providers, as well as GSM/EDGE providers in the developing world, will select Mobile WiMAX for mobile broadband wireless access while providing service continuity over their legacy networks.

4 References

[1] 3GPP TR 25.814 v7.0.0 3GPP; Technical Specification Group Radio Access Network; Physical layer aspects for evolved Universal Terrestrial Radio Access (UTRA).

[2] WiMAX Forum Mobile System Profile, V1.2.0 Sept. 2006.

[3] Source: WiMAX forum. Mr. Jacob Scheim, Ph.D., Telephone: +972 9 971 7888, Kobi.scheim@comsysmobile.com http://www.comsysmobile.com