Digital radio access network in ISDN

The authors propose a digital radio access network which provides a user/network interface at around 1.5 Mb/s with reasonable cost and high reliability. Reasons are presented that show why the 1.5-2.0-Mb/s interface is effective. Field tests confirm the correctness of the design method and that an outage time of less than 1 min/yr per radio link is achievable. The radio access network is composed of radio access links within 3-km radius zones and radio relay links of 5-km hop using quasi-millimeter waves. The application of the network with 37 radio zones covering the Tokyo metropolitan area is described