4.7 Alternate Access technologies to UTRAN

23.1213GPPArchitectural requirements for Release 1999Release 1999TS

BRAN Access

The evolved GPRS network should allow for various radio access networks. As stated in [UMTS 23.101], a modular approach in UMTS evolution is recommended. This is also in line with the recommendation from GMM. Thus, the infrastructure domain, which encompasses the core network domain and the access network domain, allows for different access techniques/networks to be used. This scenario focuses on EP BRAN HIPERLAN 2 as a complement to GSM BSS and UTRAN in order to provide broadband data services in hot spot environments.

ETSI Project BRAN (Broadband Radio Access Networks) is developing specifications for broadband wireless access systems that support data rates around 25 Mbit/s for several applications. The primary focus for HIPERLAN 2 is to provide short range wireless broadband access with controlled quality of service for use within buildings and on-campus using unlicensed radio spectrum in the 5 GHz band. HIPERLAN 2 shall provide a range of 30-50 m in a typical indoor environment and up to 150-200 m in a typical outdoor environment.

The HIPERLAN 2 specifications are expected to be finalised during 2000, hence it will be possible to introduce BRAN access in UMTS phase 1.

4.7.1 Advantages of attaching HIPERLAN 2 to UMTS

Provide UMTS with a complementary access technology for broadband data services for indoor and hot spots environments.

UMTS mobility infrastructure enables roaming also for HIPERLAN 2 terminals.

Easier multi-mode UMTS/HIPERLAN 2 service integration, enables e.g. network support for a one number service and the use of a common service platform.

UMTS subscriber management may be reused for HIPERLAN 2.

Enables the reuse of investments in core network technologies.

4.7.2 HIPERLAN 2 UMTS Interworking

UMTS will incorporate a new generic radio access network, the UMTS Radio Access Network (URAN). The URAN may include several different realisations, of which the UTRAN (UMTS Terrestrial Radio Access Network) is one. The Iu reference point forms the boundary between URAN and the UMTS core network. By connecting HIPERLAN 2 to the Iu interface, HIPERLAN 2 will form a complimentary realisation of the URAN concept for broadband data services. UMTS interworking will provide HIPERLAN 2 with roaming support using the UMTS mobility infrastructure.

Figure 4.43: HIPERLAN 2 UMTS interworking

A HIPERLAN 2 realisation of URAN should provide the same logical interface to the higher layers (i.e. layers belonging to the non-access stratum) as UTRAN. Hence, no changes in higher layers should be required. UMTS authentication, security and location management can be used over HIPERLAN 2. UMTS bearer setup requests should be mapped to the corresponding HIPERLAN 2 DLC connection. A USIM (User Service Identity Module) may be needed in a BRAN terminal supporting UMTS interworking. Handovers within a HIPERLAN 2 subsystem should be invisible to the core network. Handovers between UTRAN and HIPERLAN 2, in case of dual mode terminals, should be supported via the core network.

4.7.3 Related Actions

The same protocols over the Iu interface should be used for both UTRAN and HIPERLAN 2. However, some impact of connecting a broadband access network, capable of bit rates in the order of 100 Mbit/s, can be expected. Therefore the Iu must be flexible and future proof. Guidance and co-operation with EP BRAN on these matters should be sought.