| 摘要 |
PROBLEM TO BE SOLVED: To detect congestion simply in a wide area ubiquitous network where the congestion may not be detected by a conventional method.SOLUTION: In an uplink frame transmitted from a terminal to a base station, a random access area used for random access by a plurality of terminals, and a sharing access area used for transmission of a signal for estimating the number of terminals having transmission data are set. The terminal includes means for transmitting a signal consisting of a modulation system common to all terminals and a data string common to all terminals, at a sharing access slot transmission probability for transmitting a signal by using a sharing access slot in the sharing access area when having the transmission data. The base station includes means for measuring the number of reception success of signals in the sharing access slot of a plurality of uplink frame, and estimating the number of terminals having the transmission data on the basis of the sharing access slot transmission probability, the total number of sharing access slot, and the number of reception success in the sharing access slot. |
