Abstract: Cellular radiotelephone communication systems and methods downlink digital coded speech from a cellular radio exchange to a cellular radiotelephone base station and uplink downsampled (i.e. undersampled relative to the Nyquist rate of two samples per symbol) radiotelephone signals from the cellular radiotelephone base station to the cellular radio exchange. The downsampled radiotelephone signals are demodulated at the cellular radio exchange and the digital coded speech is modulated at the cellular radiotelephone base station. Diversity demodulation may be used at the cellular radio exchange, to diversity demodulate the downsampled radiotelephone signals at the cellular radio exchange.

Abstract: A mobile station can be used in both public cellular systems and private cellular systems, the private cellular system using select allocated frequency bands from the public cellular systems. There is disclosed herein a system for manually searching for one of the private cellular systems. The system comprises a memory storing information on select frequency bands. A transmitter and receiver is provided for communicating in the public cellular systems and the private cellular systems. An input initiates a manual search for one of the private cellular systems using the stored information on one of the select frequency bands. A programmed processor is operatively coupled to the memory, the transmitter and receiver and the input for operating the transmitter and receiver to search for the one private cellular system using the one of the select frequency bands.

Abstract: Cellular radiotelephone systems and methods communicate with cellular radiotelephones via multiple base stations. Radiotelephone traffic channels are used by the base stations for radiotelephone communications with the telephones. A common control channel is transmitted by the base stations, to control radiotelephone communications with the radiotelephones over the radiotelephone traffic channels. The common control channel is transmitted by a first one of the base stations over a first radio frequency and is transmitted by a second one of the base stations over a second radio frequency that is different from the first radio frequency. By providing a common control channel, excess control channel capacity can be reduced, thereby conserving control channel radio spectrum. Moreover, by transmitting the common control channel using multiple radio frequencies, the radio frequencies can be selected to reduce and preferably eliminate interference.

Abstract: An apparatus performs an inter-radio-infrastructure handoff (“inter-RI handoff”) in a private mobile communication system when a mobile terminal roams from a first area served by a first radio-infrastructure (RI) to a second area served by a second RI unit. The system comprises a first RI unit connected to a first radiohead (RH), and a second RI unit connected to a second RH. An inter-RI handoff is performed using a conference call.

Abstract: A cellular radiotelephone system including a Cellular Radio Exchange (CRE) and a plurality of radio heads (base stations) is deactivated, by sending an email including a deactivation message to the CRE via a communications protocol other than TCP/IP, such that the CRE deactivates the cellular radiotelephone system in response to receipt of the email including the deactivation message. Preferably, the email including the deactivation message is sent to the CRE via ANSI-41 communications protocol that is also used to communicate messages for automatic roaming, authentication, voice privacy and other services. Most preferably, the email including the deactivation message is sent to the CRE via ANSI-41 Short Message Service (SMS) communications protocol that supports email between a cellular operator system and a cellular radiotelephone system.

Abstract: Cellular radiotelephone systems and methods communicate with cellular radiotelephones via multiple base stations. Radiotelephone traffic channels are used by the base stations for radiotelephone communications with the telephones. A common control channel is transmitted by the base stations, to control radiotelephone communications with the radiotelephones over the radiotelephone traffic channels. The common control channel is transmitted by a first one of the base stations over a first radio frequency and is transmitted by a second one of the base stations over a second radio frequency that is different from the first radio frequency. By providing a common control channel, excess control channel capacity can be reduced, thereby conserving control channel radio spectrum. Moreover, by transmitting the common control channel using multiple radio frequencies, the radio frequencies can be selected to reduce and preferably eliminate interference.

Abstract: Methods and systems for measuring signal noise of supervisory audio tones (SATs) in radiocommunication systems are disclosed. Exemplary embodiments involve extracting a real component from a received SAT signal, removing the SAT signal portion and examining the remainder to determine a noise component present in the SAT. The noise component can be compared with a signal strength measurement to obtain a signal-to-noise ratio.