Abstract:
The invention provides for path optimization for routing of a communication session in a network having a plurality of core networks (110) coupled to a plurality of access networks (120). Both a core network and an access network perform the path optimization by determining a plurality of possible paths to a plurality of target access points to form a target matrix, determining a corresponding route preference factor for each possible path of the target matrix, and selecting, from the target matrix, a possible path having an optimal route preference factor. An overall or complete path, for routing of the communication session, is then determined either by combining the selected possible paths, or by selecting one possible path as a complete path. The route preference factor, for each possible path, is determined based upon various routing variables, such as quality of service, bandwidth for the communication session, route complexity, interconnect cost, routing cost; resource loading, resource availability, and operator preference for traffic biasing.
Abstract:
A packet switching system (100) employs packet reassembly hardware (214) in a packet switch (140) to improve overall system throughput during the handling of transmission packets (310) that require reassembly. In this manner, reassembly is accomplished with minimal processor (110) intervention and without having to duplicate the message data portion (312) of a transmission packet (310) into a different memory location prior to retransmission.
Abstract:
A common communication controller (17) is linked to a plurality of peripheral devices (28) by a network interface bus (26). Packets containing information is communicated between the controller and the peripherals over the bus which consists of a parallel packet bus and a plurality of control lines utilized to implement a communication protocol which increases the efficiencies of packet communications by the utilization of additional direct command lines between the communications controller (17) and peripherals (28).
Abstract:
The invention provides for path optimization for routing of a communication session in a network having a plurality of core networks (110) coupled to a plurality of access networks (120). Both a core network and an access network perform the path optimization by determining a plurality of possible paths to a plurality of target access points to form a target matrix, determining a corresponding route preference factor for each possible path of the target matrix, and selecting, from the target matrix, a possible path having an optimal route preference factor. An overall or complete path, for routing of the communication session, is then determined either by combining the selected possible paths, or by selecting one possible path as a complete path. The route preference factor, for each possible path, is determined based upon various routing variables, such as quality of service, bandwidth for the communication session, route complexity, interconnect cost, routing cost; resource loading, resource availability, and operator preference for traffic biasing.
Abstract:
A wireless in-building telecommunications system for voice and data communications is disclosed having at least one node (101) arranged for linking to the PSTN (151) and at least one digital information source (153, 155, 157, 159) multiplicity of user modules (103) (UM's) linked to the node via a shared RF communications path (107). Each UM is coupled to a voice telephone instrument (127) and to one or more data terminals (165). The UM's communicate with the node by exchanging fast packets via the common RF path (107). The node also includes a fast-packet-switched mechanism controlled by a bandwidth allocating scheme to prevent collisions of packets as they are transmitted between the various units (101, 103) (nodes and/or user modules) that may be accessing the RF path (107). Also disclosed is a method for allocating the required bandwidth to each of the users of the common communications path in a wireless in-building telephone system. The invention provides for the combination of both voice and data in a single switch using a common packet structure. It allows for the dynamic allocation of bandwidth based on system loading. This includes not only bandwidth within the voice or data areas of the frame, but also between the voice and data portions. It also synchronizes the transfer of the data and the allocation of bus bandwidth.
Abstract:
An encryption circuit that operates with substantially zero delay. Using programmable keys and polynomials, the encryption algorithm can be constantly changed to thwart any unintended receiving parties from decoding the data. A key (101) and a polynomial (102) are loaded into registers. The key is then loaded into a shift register and shifted through XOR gates (106) at a programmable rate. The other input of the XOR gates comes from the result of ANDing (103) a disable signal, the polynomial register (102), and the last stage of the shift register (104). Eight bits of the shift register outputs are XOR'ed with the input data to be encrypted. The output of these XOR gates (105) is the encrypted data.
Abstract:
A packet switching system (100) having a packet switch (140) employs an acknowledgement scheme in order assure the delivery of all fragments (310) comprising a fragmented data packet (300) to improve overall system throughput during the handling of packets (310) that require reassembly. When packet fragments (310) are lost, corrupted or otherwise unintelligible to a receiving device (92, 94), the acknowledgement scheme permits retransmission of the missing data. In addition, a second acknowledgment signal is scheduled by system processing resources (110) in order to verify the successful delivery of all retransmitted data.
Abstract:
An antenna selection technique is used in an RF communication system in which user modules (UM1-UM5) communicate with at least one node (N1-N2). The UM's (UM1-UM5) and nodes (N1, N2) each have multiple antennae. The combination of each UM and node antenna is evaluated at the UM. Based on at least signal quality, the UM (UM1-UM5) selects its antenna and the best node antenna for use. An alternate antenna is selected if a person is determined to be present in a predetermined area adjacent a UM (UM1-UM5) corresponding to a predetermined RF power level.
Abstract:
An antenna selection technique is used in an RF communication system in which user modules (UM1-UM5) communicate with at least one node (N1-N2). The UM's (UM1-UM5) and nodes (N1, N2) each have multiple antennae. The combination of each UM and node antenna is evaluated at the UM. Based on at least signal quality, the UM (UM1-UM5) selects its antenna and the best node antenna for use. An alternate antenna is selected if a person is determined to be present in a predetermined area adjacent a UM (UM1-UM5) corresponding to a predetermined RF power level.