Patent ID: 7920506
Filing Date: 2011-04-05
Classification: H04B

Abstract:
1. A transmission schedule constructing apparatus capable of constructing a transmission schedule for stations on a power line communication network, the transmission schedule being for use in time division multiple access of the stations on the power line that is a communication medium, the transmission schedule constructing apparatus comprising: an allocation request receiving section operable to receive a schedule allocation request from within the transmission schedule constructing apparatus and/or from other stations, the schedule allocation request designating a parameter relating to transmission quality; and a transmission schedule constructing section operable to construct the transmission schedule based on a cyclic change in a transmission quality of the power line depending on an alternating current power source cycle and based on the parameter relating to transmission quality and designated in the schedule allocation request, wherein the parameter relating to transmission quality and designated in the schedule allocation request describes a transmission rate requested for data to be scheduled, wherein a scheduling policy for construction of the transmission schedule and relating to the transmission rate is previously set in the transmission schedule constructing section, wherein a rule is set in the scheduling policy, such that the rule set in the scheduling policy allocates a time zone, at which a higher physical transmission rate is provided, for data requesting a higher transmission rate, when the data is requesting the higher transmission rate and other data is requesting a lower transmission rate, and wherein the transmission schedule constructing section constructs the transmission schedule by (i) resetting a current transmission schedule when a new schedule allocation request is received by the allocation request receiving section, and (ii) trying to perform an allocation (a) for all schedule allocation requests currently received and (b) that is in accordance with the scheduling policy and the rule set in the scheduling policy, so that the transmission rate described in the parameter is satisfied, such that, when the allocation is successful for all of the schedule allocation requests, the transmission schedule is constructed using the successful allocation and is output, and such that, when the allocation is not successful for all of the schedule allocation requests, the reset transmission schedule is recovered to be used as the transmission schedule.