A seamless solution transparently addresses the characteristics of nomadic systems, and enables existing network applications to run reliably in mobile environments. The solution extends the enterprise network, letting network managers provide mobile users with easy access to the same applications as stationary users without sacrificing reliability or centralized management. The solution combines advantages of existing wire-line network standards with emerging mobile standards to create a solution that works with existing network applications. A Mobility Management Server coupled to the mobile network maintains the state of each of any number of Mobile End Systems and handles the complex session management required to maintain persistent connections to the network and to other peer processes. If a Mobile End System becomes unreachable, suspends, or changes network address (e.g., due to roaming from one network interconnect to another), the Mobility Management Server maintains the connection to the associated peer task—allowing the Mobile End System to maintain a continuous connection even though it may temporarily lose contact with its network medium. In one example, Mobility Management Server communicates with Mobile End Systems using Remote Procedure Call and Internet Mobility Protocols.

Method and apparatus for providing mobile and other intermittent connectivity in a computing environment

An apparatus and method is provided for transparent communication between a remote or mobile device and a fixed communication host network. The apparatus and method may include a remote network controller that logically resides between the host network and the existing infrastructure(s) that are used to provide communications network contact with one or more remote devices. The remote network controller is connected to the host communication network as a protocol-appropriate communications controller so that remote devices are indistinguishable to the host network from the locally-attached devices. Each remote device may be provided with an asynchronous serial data interface to communicate with a mobile data controller. The mobile data controller, in combination with the remote network controller, provides end-to-end data communication such that incompatible protocols are transparent to the remote device and host communication network. A router may be provided which selects a communications network in accordance with user configured parameters. The router communicates over a plurality of incompatible networks and is capable of using a variety of different protocols. Switching between the plurality of incompatible networks is transparent to the remote device and host communication network.

Apparatus and method for intelligent routing of data between a remote device and a host system

The invention can enable monitoring of the display of content by a computer system. Moreover, the invention can enable monitoring of the displayed content to produce monitoring information from which conclusions may be deduced regarding the observation of the displayed content by an observer. The invention can also enable monitoring of the display at a content display site of content that is provided by a content provider site over a network to the content display site. Additionally, the invention can enable the expeditious provision of updated and/or tailored content over a network from a content provider site to a content display site so that the content provider's current and appropriately tailored content is always displayed at the content display site. Aspects of the invention related to transfer of content over a network are generally applicable to any type of network. However, it is contemplated that the invention can be particularly useful with a computer network, including private computer networks (e.g., America Online™) and public computer networks (e.g., the Internet). In particular, the invention can be advantageously used with computer networks or portions of computer networks over which video and/or audio content are transferred from one network site to another network site for observation, such as the World Wide Web portion of the Internet.

Content display monitor

A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.

Ofdma with adaptive subcarrier-cluster configuration and selective loading

A hierarchical communication system, arranged in a spanning tree configuration, is described in which wired and wireless communication networks exhibiting substantially different characteristics are employed in an overall scheme to link portable or mobile computing devices. Copies of data, program code and processing resources are migrated from their source toward requesting destinations based on request frequency, communication link costs and available local storage and/or processing resources. Each appropriately configured network device acts as an active participant in network migration. In addition, portable two-dimensional (2-D) code reading terminals are configured to wirelessly communicate compressed 2-D images toward stationary access servers that identify the code image through decoding and through comparison with a database of images that have previously been decoded and stored.

Hierarchical communication system providing intelligent data, program and processing migration

In a cellular mobile telephone system of the type having TDMA channels, a plurality of mobile station operate at either a full rate or a half rate. If the mobile stations are operating on the periphery of a cell they are assigned to full rate channels. If the mobile stations are operating in the vicinity of the base station, they are assigned to half rate channels. The mobile station are reassigned from full rate to half rate channels depending upon a measured parameters relating to signal strength or quality, such as the bit error rate of communications between the mobile station and the base station. If the measured bit error rate between the mobile station and a neighboring station is less than the bit error rate between the mobile station and its presently assigned base station, the mobile station is handed off to the neighboring base station.

Handoff of a mobile station between half rate and full rate channels

A method and apparatus for frequency planning in a multi-system (A, B, C) cellular communications network is disclosed in which a plurality of systems operate over a frequency range comprising a plurality of frequency bands. The systems (A, B, C) each provide communications services to a plurality of subscribers (660) located within substantially the same geographic region. Each of the systems (A, B, C) is assigned one or more of the network frequency bands for use as control channels (700, 730). The systems then share the unassigned frequency bands to provide communications service (710, 720). The systems may share the frequency bands without coordination or synchronization or, as an alternative, the sharing may be controlled by a processor.

Method and apparatus for frequency planning in a multi-system cellular communications network

The invention relates to a method in a mobile radio system having both digital and analog radio channels. An object of the invention is that a connection established on a digital radio channel often shall be possible to maintain even when the time dispersion on available digital radio channels exceeds the designed maximum time dispersion of equalizers in receiving stations. According the invention equalizers in the receivers of the system may be designed for a smaller maximum time dispersion than the total time dispersion the whole system shall be capable to handle. Instead handoff is made to an other channel when the time dispersion of a used digital channel tends to become too big. When an other digital radio channel with low time dispersion is available handoff is preferably done to this channel. Alternatively or in the absence of such a digital radio channel handoff is performed to an analog radio channel.

Method of maintaining an established connection in a mobile radio system comprising both analog and digital radio channels

The invention relates to a cellular digital mobile radio system including base stations (Bm, Bn) and mobile stations (MS1, MS2) with transmitters and receivers. The invention also relates to a method of transmitting message information digitally between mobile and base stations in such a system. In accordance with the invention, at least two base station transmitters (Bma, Bmb, Bna, Bnb) at a given transmitting distance from each other are assigned to each of certain cells (Cm, Cn) within a restricted geographical area. The base station transmitters which are assigned to the same cell transmit digitally modulated radio signals within the same frequency range at least partially simultaneously to the mobile stations of the cell. The radio signals from different base station transmitters associated with the same cell are digitally modulated with the same message information to the mobile stations in the cell. Different base station transmitters (9A, 9B) preferably transmit the digitally modulated radio signals with the same message information to a given mobile station with a given mutual transmission time shift. Here, the transmission time shift is selected individually for each mobile station, such that corresponding digitally modulated radio signals with the same message information to a given mobile station from different base station transmitters arrive practically simultaneously at the mobile station.

Cellular digital mobile radio system and method of transmitting information in a digital cellular mobile radio system

A method in a mobile radio station to select one of a number of dedicated control channels (DCCH1-21) which are transmitted from a number of base stations (B1-B21) in a mobile radio system. In the mobile station there is an equalizer to compensate for the multipath propagation characteristics of the radio medium between the mobile station and a certain base station. This equalizer is power consuming and should not be used if not necessary. According to the method an investigation is carried out in the mobile station whether or not the equalizer can be disconnected during the initialization of a call from the mobile to a base station. The signal quality of the dedicated channel (DCCH1) which has the greatest signal strength is measured without the equalizer. If the signal quality is not acceptable, a new detection is made with the use of the equalizer. If the signal quality then is acceptable another detection is made without equalizer on the dedicated control channel (DCCH2) which has the next strongest signal and if this detection revealed an acceptable signal quality the base station (B2) transmitting this control channel is selected by the mobile station for the further call progress.

Jan Erik Uddenfeldt

Papers

Handoff of a mobile station between half rate and full rate channels

Method and apparatus for frequency planning in a multi-system cellular communications network

Method of maintaining an established connection in a mobile radio system comprising both analog and digital radio channels

Cellular digital mobile radio system and method of transmitting information in a digital cellular mobile radio system

Method for reducing equalizer usage in mobile radio communication systems