The AIRSTAR-WLL system, PHS-based Wireless Local Loop (WLL) solution, has been co-developed by UTStarcom, Inc., a manufacturer of digital loop carrier and fiber transport systems, and Matsushita Communication Industrial Co., Ltd. (Panasonic) of Japan.By taking advantage of the advanced and widely deployed Radio Frequency Systems of Panasonic and the state-of-the-art New-Generation Telephony Switch interfaces and transmission techniques of UTStarcom, the AIRSTAR-WLL is a very advanced and cost-effective WLL solution. AIRSTAR-WLL is currently in pilot projects in China and various countries in South East Asia.

Service providers in emerging countries seek to offer quick, reliable and inexpensive service to meet their subscribers growing needs. A PHS-WLL system is an advanced, low-cost alternative to traditional fixed telephone system. It supports digital 32-kbps air channels for great sounding voice and voice-band data, provides billing and required features such as toll like voice quality, authentication, encryption, minimal network planning and the ability to interface to the Service Node (SN) with a very flexible network interface.
Protocol flexibility to interfaces to different SN and physical transport flexibility, to make use of existing infrastructure, are required to meet the needs of rapid roll-out and low-cost WLL solutions.
AIRSTAR-WLL extends the SN switch to a remote area by means of UTStarcoms’s AN-2000 Access Server Central Office Terminal (COT) already deployed by more than 200 PTT operators worldwide. The system offers transmission solutions based on users needs through analog or digital connections. The physical transport to the COT can be 2-wire, E-1, fiber or microwave.

\ Analog Interface: The SN connects to the COT using a 2W loop start interface, exactly as with wired telephone subscribers. This permits providers to install a flexible mix of wired and wireless capacity without constraints or need to reconfigure the SN switch.
\ Digital Interface: V5.1 and V5.2 options eliminate the expense of COT and SN line cards thus providing an extremely cost effective solution. V5.2 has the additional benefit of providing a concentrating interface between the SN and the WLL Access Controller (WAC). This concentrating interface reduces the back-haul bandwidth requirements which can provide significant cost savings such as when microwave links are utilized.
Next, the WAC performs traffic concentration on the WLL Call Station (WCS) and provides power to the WCSs. Up to 32 WCSs, strategically placed for traffic requirements, are controlled by one WAC.
The WCS terminals can be located indoors or outdoors. They are line powered over ordinary twisted-pair cabling and can be added wherever there is a need to expand system capacity.
The WLL Subscriber Units (WSU) are installed indoors. Depending on the WSU proximity to the WCS, an internal omni or an external high-gain antenna is utilized. The customer’s phone connects to an RJ-11 jack on the WSU.