# US 5,710,973 A · Method for allocating idle channels of a cellular mobile telephone system for use in a microcellular system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,710,973 A - Document ID: US5710973A - Status: Granted - Kind: A - Application number: 08/565,965 - Filed: 1995-12-01 - Granted: 1998-01-20 - Earliest claimed: 1991-10-21 - Assignees: Matsushita Electric Industrial Co., Ltd. - Inventors: Jun Yamada; Masaki Terashima; Kenichi Ooyama; Eiji Ohmori - Web page: https://patentgrep.com/patent/US5710973A ## CPC - H04W 16/14: Spectrum sharing arrangements {between different networks} - H04W 16/32: Hierarchical cell structures - H04W 28/16: Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service] - H04W 72/541: using the level of interference - H04W 88/06: adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals - H04W 16/12: Fixed resource partitioning - H04W 16/24: Cell structures - H04W 24/00: Supervisory, monitoring or testing arrangements - H04W 84/042: {Public Land Mobile systems, e.g. cellular systems} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract In a microcellular system operated in the same frequency band as a cellular system, an interference-free channel is automatically searched and allocated. The microcellular system which shares the frequency band with the cellular system comprises a control unit, a base station and a multi-channel selecting receiver. The multi-channel selecting receiver monitors a use status of cellular channels of the band by repetitively scanning voice channels for a scanning time period substantially longer than the duration of any single voice communication to detect idling channels and allocates them to its own system. Whenever a communication request is issued, the base station detect a channel not used by its own system from the idling channels and allocates it for communication. ## Claims ### Claim 1 A method by which a microcellular system (MCS) sharing voice channels in a frequency band allocated to a cellular mobile telephone system (CMTS) selects channels therefrom for allocation to said MCS, said MCS operating in the same area as a local cell of said CMTS to which said CMTS has allocated particular ones of said CMTS voice channels, wherein said MCS performs the steps of: (a) repetitively scanning said CMTS voice channels for a scanning time period substantially longer than the duration of any single voice communication with a receiver in said MCS, said scanning including CMTS voice channels not allocated to said local cell, to determine a maximum reception level for each of said CMTS voice channels during said scanning time period; (b) generating and storing a list of idle voice channels based solely upon information obtained as a result of said scanning, wherein said maximum reception level of each CMTS voice channel on said list is below a predetermined threshold value; (c) allocating at least one channel from said list to said MCS for use as a MCS control channel; and (d) allocating channels from said list to said MCS for use as voice channels by said MCS. ### Claim 2 (depends on 1) The method of claim 1, wherein a base station of said MCS, in response to receiving a communication request, performs the further steps of: receiving information from a controller of said MCS identifying the voice channels allocated to said MCS; sequentially scanning said allocated voice channels to determine an available voice channel having a reception level below a predetermined threshold at the time of said communication request; and assigning said available voice channel to a terminal operating within said MCS to service said communication request. ### Claim 3 (depends on 1) The method of claim 1 wherein said MCS operates within a plurality of zones, each zone having at least one of said MCS control channels for transmitting system information. ### Claim 4 (depends on 1) The method of claim 1 wherein said MCS operates within a plurality of zones, and at least one of said MCS control channels is operated by a controller of said MCS in a time division multiplexed (TDM) manner to serve said plurality of zones, wherein said TDM control channel transmits control information in respective time slots designated to respective ones of said zones. ### Claim 5 (depends on 1) The method of claim 1 wherein said MCS operates within a plurality of zones and at least one of said MCS control channels is operated in a time division multiplexed (TDM) manner to serve said plurality of zones, each of said zones further including at least one control channel at a different frequency. ### Claim 6 (depends on 1) The method of claim 1, wherein a terminal operating within said MCS determines an MCS control channel by performing the steps of: scanning said CMTS voice channels to identify one or more CMTS voice channels having a received signal strength greater than a predetermined threshold; scanning said identified one or more CMTS voice channels to locate a CMTS voice channel which carries control information for said MCS. ### Claim 7 (depends on 6) The method of claim 6 wherein said terminal accesses said MCS control channel for servicing a communication request. ### Claim 8 (depends on 6) The method of claim 6 wherein only a portion of said CMTS voice channels including an MCS control channel is scanned by said terminal. ### Claim 9 A microcellular system (MCS) which shares the voice channels of a frequency band allocated to a cellular module telephone system (CMTS) and which operates in the same area as a local cell of said CMTS to which said CMTS has allocated particular ones of said CMTS voice channels, comprising: (a) cellular channel scanning receiver for repetitively scanning said CMTS voice channels, including CMTS voice channels not allocated to said local cell, over a scanning time period substantially longer than the duration of any single voice communication, to identify idle voice channels, based solely on said scanning, having a reception level during said scanning time period that is lower than a predetermined value; a control unit; and means for transmitting to said control unit a list identifying said idle voice channels, said control unit allocating said idle voice channels to said microcellular system or thereafter servicing any communication requests to said MCS. ### Claim 10 (depends on 9) The microcellular system of claim 9, further comprising at least one base station having a receiver for scanning said idle voice channels in response to a communication request to identify an idle voice channel having a reception level that is lower than a predetermined value at the time of said communication request, said base station assigning said identified idle voice channel to a terminal to service said communication request.