Abstract: Improved apparatus for a radio communication system having a multiplicity of mobile transceiver units selectively in communication with a plurality of base transceiver units which communicate with one or two host computers for storage and manipulation of data collected by bar code scanners or other collection means associated with the mobile transceiver units. A network controller provides selective interface means to be employed between the host computers and the base transceivers whereby low data rate base transceivers may be utilized with the network controller while spread spectrum or high data rate networked base transceivers may be also utilized. The network controller may allow selection of interface means for three of its ports from its front panel with use of three input keys. The network controller is entirely external to the host computer or computers, and can couple to a variety of commonly encountered host ports.

Abstract: Improved apparatus for a radio communication system having a multiplicity of mobile transceiver units selectively in communication with a plurality of base transceiver units which communicate with one or two host computers for storage and manipulation of data collected by bar code scanners or other collection means associated with the mobile transceiver units. A network controller provides selective interface means to be employed between the host computers and the base transceivers whereby low data rate base transceivers may be utilized with the network controller while spread spectrum or high data rate networked base transceivers may be also utilized. The network controller may allow selection of interface means for three of its ports from its front panel with use of three input keys. The network controller is entirely external to the host computer or computers, and can couple to a variety of commonly encountered host ports.

Abstract: In an exemplary embodiment, a base station maintains RF communication with mobile units using a polling protocol which may communicate at a higher or lower data rate, depending on the channel conditions. The base station transmits a general polling message at the lower data rate, and, associated therewith, transmits a test pattern for evaluation by the mobile units. Upon receipt of the transmissions, the mobile units analyze the test pattern to determine whether communication at the higher data rate is possible. Based on the determination, the mobile units select the appropriate rate to transmit data messages. The test pattern can be associated with a query from a mobile unit having a message to send, or with a contention polling message from the base.

Abstract: An apparatus and a method for routing data in a radio data communication system having one or more host computers, one or more intermediate base stations, and one or more RF terminals organizes the intermediate base stations into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Communication between the host computer and the RF terminals is achieved by using the network of intermediate base stations to transmit the data.

Abstract: In an exemplary embodiment, a test signal is sent by a base station at a suitable point in a communications protocol. According to the evaluation of the test signal transmission, a relatively high data rate or a lower more conservative data rate is selected by a mobile unit for the transmission of a relatively lengthy data message. The test signal can be associated with a query from a mobile unit having a message to send, or with a contention polling message from the base. Such test signal can be transmitted at the lower data rate where its transmission characteristics (e.g. signal strength, jitter or quality of transmission of known information) can be used to predict probable feasibility of transmission at the higher data rate, but most preferably the test signal is part of a high data rate contention poll which may alternate with a low data rate contention poll.

Abstract: In an exemplary communications system a multiplicity of mobile terminals are to share a communications link with a primary processor. The primary processor may transmit a multiterminal polling signal defining a series of successive response time slots which the terminals may randomly select. A terminal wishing to send a message transmits a brief response burst in the selected time slot giving its identification. The primary processor may then sequentially poll specific individual terminals having messages to send. The primary processor may maintain a record of currently active terminals and/or of collisions (where more than one terminal seeks to transmit in the same response time slot), and as needed may automatically send e.g. with its multiterminal poll, a time slot number change, creating a greater or lesser number of time slots for future use by the active terminals.

Abstract: In an exemplary communications system a multiplicity of mobile terminals are to share a communications link with a primary processor. The primary processor may transmit a multiterminal polling signal defining a series of successive response time slots which the terminals may randomly select. A terminal wishing to send a message transmits a brief response burst in the selected time slot giving its identification. The primary processor may then sequentially poll specific individual terminals having messages to send. The primary processor may maintain a record of currently active terminals and/or of collisions (where more than one terminal seeks to transmit in the same response time slot), and as needed may automatically send e.g. with its multiterminal poll, a time slot number change, creating a greater or lesser number of time slots for future use by the active terminals.