UMTS Forum Report 28, March 2003

Introduction

This report is another Report from the UMTS Forum on the impact of WLANs on 3G. Earlier reports (UMTS Forum Reports 22, 24 and 25) deal with quantitative and qualitative aspects [1, 2] as well as with WLAN spectrum and regulatory aspects [3]. In its Report 22 'Impact & Opportunity: Public Wireless LANs and 3G Business Revenues' UMTS Forum concluded that UMTS/3G and Wireless LAN are complementary rather than competitive technologies.

This report has been prepared by UMTS Forum with the following objectives:

• To carry out UMTS TDD market survey to obtain information on likely market introduction of TDD, status of manufacturers developments, features of TDD terminal and infrastructure equipment, etc.

• To provide a relative assessment of UMTS TDD & WLAN technologies.

Section 2 describes the results of the UMTS TDD market survey. This market survey covers industry activities and views on TDD. A questionnaire was distributed to all members of the UMTS Forum. Overall, eight completed responses were received by the UMTS Forum Secretariat. The reader is reminded that the sample response is too small to be statistically representative of the plans and intentions of the UMTS/3G operators and vendors as a whole. Therefore, the results of the TDD survey in section 2 must be carefully viewed with this in mind.

Section 3 provides a high level overview of UMTS TDD technology, including traffic capacity etc.

Section 4 of the report provides a comparison of UMTS TDD and WLAN technology from a deployment scenario perspective and compares the overall system capabilities of the two technologies.

Note on TDD Terminology: 3GPP standards distinguish between two types of UMTS TDD technology, which are characterized by different chip rates and consequently different bandwidths. Specifically the chip rates are 3.84 Mcps and 1.28 Mcps, with the corresponding bandwidths being 5 MHz and 1.6 MHz. Accordingly, the two TDD types are referred to in literature as Wideband TDD (WTDD) and Narrowband TDD (NTDD) or as High Chip Rate (HCR) TDD and Low Chip Rate (LCR) TDD. In this report, HCR/LCR TDD terminology is used.