Abstract:
A dual mode cellular cordless portable radiotelephone (101) preferentially selects the cordless base station (115) over the cellular system (103) when in range of the cordless base station (115). When the cordless cellular portable (101) is operating in the cellular mode, the radio channel associated with the cordless base station (115) is sampled for a predetermined time. When a signal on the sampled cordless base station (115) channel is detected, the cordless portable (101) moves to the cordless mode and remains in the cordless mode for as long as the signal quality of the signal on the cordless base station (115) channel exceeds a predetermined value.
Abstract:
A method generally improves the frequency accuracy in a communications system without requiring the use of accurate frequency references in all of the stations or types of stations. An accurate frequency reference is utilized in one of the stations or station types. The reference frequencies of the remaining stations or station types can be adjusted based upon the accurate reference frequency in one of the stations. In particular, a method for adjusting referene frequencies in a communication system comprising a portable station, a residential base station, and a public base station which generates a first reference frequency is characterized by the steps of adjusting (512) a second reference frequency in the portable station based upon the first reference frequency and adjusting (514) a third reference frequency of the residential base station based upon the second reference frequency.
Abstract:
A cellular cordless telephone (101) has a first mode of operation for making and receiving cellular telephone calls via a cellular telephone system (103) and a second mode of operation for making and receiving cordless telephone calls on a cellular radio channel used by a cordless base station (115). The cellular cordless telephone (101) automatically selects either the first mode or the second mode and receives from the cellular system (103) when operating in both the first mode and the second mode. The cellular cordless telephone (101) transmits in the cellular system (103) with an output power having a predetemined set of power magnitude steps when operating in the first mode and transmits on a cellular radio channel to the cordless base station (115) with a power level selected to be no greater than the lowest step of power magnitude of said predetermined set of power when operating in the second mode.
Abstract:
A method generally establishes a communication link in a communiction system when a cordless base station has been authenticated to communicate with authorization equipment, and the authorization equipment has been authenticated to communicate with the cordless base station. Preferrably, one or more random numbers are transmitted between the cordless base station and the authorization and call routing equipment (502, 504) to establish the communication link.
Abstract:
A call routing system includes an authorization and call routing equipment (ACRE) (117), a cordless base station (115) connected by a wireline network (111) having caller identification. The cordless base station (115) initiates a call to the ACRE (117), which receives the cordless base station's (115) telephone number. The ACRE (117) then uses the telephone number for routing subsequent telephone calls to the cordless base station (115). The cordless base station (115) can receive and store caller identification information and transmit this information to a radiotelephone (101).
Abstract:
The method of the present invention generally validates a communication link in a communication system. In particular, the method validates a communication link between a cordless base station and authorization and call routing equipment by authenticating the cordless base station to communicate with said authorization equipment (603) and authenticating the authorization equipment to communicate with the cordless base station (604). Preferably, the step of authenticating the cordless base station is based upon a first random number generated within the authorization equipment (502) and the step of authenticating the authorization equipment is based upon a second random number generated within the cordless base station (504). A communication link is allowed between the cordless base station and the authorization equipment when both the cordless base station and the authorization equipment have been authenticated (614).
Abstract:
A system for choosing a communication having an ACRE (117), a radiotelephone (101) and a cordless base station (115). The cordless base station (115) connected to the ACRE (117) by a wireline network (111) and receiving a message (506) authorizing the use of a subset of channels. The cordless base station (115) determining which of the set of channels meets a channel quality criteria and only communicating over a channel, to the radiotelephone (101), if the channel meets the channel quality criteria and is authorized.
Abstract:
A communication system has a portable cellular cordless (PCC) radiotelephone (101) which receives a data stream from a cordless base station (115) when the PCC (101) is not engaged in a telephone call. The data stream has a repeat indication field (508) and a message field (506) that the PCC (101) uses to determine if the message has already been received. If the PCC (101) determines the message was already received, the PCC (101) turns off its receiver (401) for a duration of time slightly less than the message field time. This results in a power savings for the PCC (101).
Abstract:
A communication system has a PCC (101) which receives a data stream from a cordless base station (115). The cordless base station (115) transmits an indication in the data stream that it is going to beguin a scan. While the cordless base station (115) is scanning, the PCC (101) performs a scan of its own. The PCC (101) also performs a scan when it determines that a message is a repeat and has been previously received.
Abstract:
A cellular cordless telephone (101) may receive cellular telephone calls via a cellular telephone system (103) and receive telephone calls on a system having a limited radio coverage area (113, 115). To reduce the amount of time spent in monitoring the sub-data channel of the limited coverage area system, a timing signal is generated which represents the period of time spent monitoring the radio channel (803). During the monitoring, a predetermined number of data words transmitted on the limited radio coverage area radio channel system are received. When a first received data word is detected (811), an allowed monitoring time value is adjusted to be the sum of the value of the timing signal and the product of a determined number of received words to be detected and the time required for each word (823). This adjusted value of the monitoring time value is compared to the value of the timing signal (825) and when the adjusted monitoring time value equals or exceeds the timing signal value, the monitoring of the radio channel ceases (825).