| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize a low-cost and efficient Point-to-Multipoint radio access system by securing frequency bands enough for uplink or downlink, respectively. SOLUTION: For the downlink (from radio base station to radio subscriber's terminal) and the uplink (from radio subscriber's terminal to radio base station), a combination of various kinds of radio bands is used from, for example, quasi- millimetric wave/millimetric wave frequency bands including 26 GHz, 28 GHz, 38 GHz, and 42 GHz, bands requiring no license such as 2.4 GHz ISM band, 5.3 GHz frequency band, 60 GHz frequency band, and light. For example, quasi- millimetric/millimetric wave frequency bands having a variety of bands are used for the downlink including access to the Internet which uses asymmetric traffic and therefore requires a large capacity, while using 2.4 GHz ISM band which requires no license or the like for the uplink requiring a small capacity, to reduce the subscribers' terminal cost.</p> |
