Resource allocating method among mobile-stations in distribution communication network

A method of resource allocation among mobile stations in a distributed communication network in which the mobile stations are located in a short distance communication range of limited communication resources, communicate with each other without having to communicate with a sensor node, and allocate the limited communication resources, the method of resource allocation comprising:

• (a) a mobile station located in a certain area, checking according to a resource allocation communication protocol through a listen time slot to see whether there is another mobile station allocating a localization time slot currently existing in the same area;
• (b) if perceiving the existence of said another mobile station, the mobile station allocating the localization time slot for itself at the time point that said another mobile station finishes using the localization time slot by extending or shortening its listen time slot;
• (c) the mobile station performing location measurement of its location by transmitting an RF signal and ultrasonic waves through the localization time slot to sensor nodes;
• and
• (d) the mobile station receiving RF signals from each of three or more sensor nodes, each containing calculated distance information, wherein the received information is used by a location tracer within the mobile station to measure the mobile station's location;
• wherein time slots used by the mobile station include the listen time slot to receive RF signals from the other mobile stations, and the localization time slot for location measurement;
• wherein the localization time slot for location measurement is composed of an access time period for access and an operation time period for actual measurement of location;
• wherein the access time period refers to access delay time period to avoid collision with the time slot of the other mobile stations, which includes a priority access time period and a random access time period;
• wherein the mobile station transmits ultrasonic signal at the start of the operation time period and at the same time as a request period for distance information to sensor nodes which will be used along with the ultrasonic signal by the sensor nodes for distance calculation;
• wherein after the period of ultrasonic transmission is completed, three or more sensor nodes each in its own reply time period sends reply signal, loaded with calculated distance information to be used for measuring the mobile station's location;
• and
• wherein at operation (a), the mobile station perceives the existence of said another mobile station based on a radio frequency (RF) signal for location measurement which is received from said another mobile station through the listen time slot.