Information Theory and Reliable Communication

The present invention is generally directed to a system for monitoring a variety of environmental and/or other conditions within a defined remotely located region. In one aspect, a system is configured to monitor utility meters (613) in a defined area. The system is implemented by using a plurality of wireless transmitters (614), each integrated into a sensor (612) adapted to monitor a particular data input. The system also includes a plurality of transceivers (221) that are dispersed throughout the region at defined locations. The system uses a local gateway (210) to translate and transfer information from the transmitters to a dedicated computer (260) on a network (230). The dedicated computer collects, compiles and stores the data for retrieval upon client demand across the network. The computer further includes means for evaluating the received information and identifying an appropriate control signal to be applied at a designated actuator.

System and method for monitoring and controlling remote devices

Telephone calls, data and other multimedia information is routed through a hybrid network which includes transfer of information across the internet. A media order entry captures complete user profile information for a user. This profile information is utilized by the system throughout the media experience for routing, billing, monitoring, reporting and other media control functions. Users can manage more aspects of a network than previously possible, and control network activities from a central site. The hybrid network also contains logic for responding to requests for quality of service and reserving the resources to provide the requested services.

System and method for providing requested quality of service in a hybrid network

The distribution of Euclidean distances in Poisson point processes is determined. The main result is the density function of the distance to the n-nearest neighbor of a homogeneous process in Ropfm, which is shown to be governed by a generalized Gamma distribution. The result has many implications for large wireless networks of randomly distributed nodes

On distances in uniformly random networks

The information theoretic approach and the collision resolution approach to multiaccess channels are reviewed in terms of the underlying communication problems that both are modeling. Some perspective on the strengths and weakness of these approaches is given, and the need of a more combined approach focused on coding and decoding techniques is argued.

A perspective on multiaccess channels

The communications network includes a plurality of interconnected nodes and communication links between nodes. Computing apparatus in provided for determining a shortest path from a starting node to a destination node. The computing apparatus is adapted so that each node forms a routing tree having nodes with indentities, branches with weights, and a distinguished node called a root. The routing tree is the estimated shortest path to all of the nodes and each node communicates its routing tree to each adjacent node. Upon receipt of a routing tree by a reference node from an adjacent node, the reference node stores the routing tree and produces a large tree having roots and branches by placing the reference node as the root of the large tree and creating branches from the reference node to the roots of the routing trees of the adjacent nodes. The lengths of the branches are equal to the lengths of the links from the reference node to the adjacent nodes. A breadth first search of the large tree is performed to determine a connected subset of the large tree where each node identity appears only once. The connected subset forms the new routing tree for the reference node. If the new routing tree differs from the previous routing tree, the new routing tree is broadcast to all adjacent nodes and the procedure is repeated until no new tree differs from a previous tree, thereby defining a final routing tree. The final routing tree includes the shortest path from the reference node to all connected nodes.

Communication system for sending an identical routing tree to all connected nodes to establish a shortest route and transmitting messages thereafter

: Communication concentrators perform the basic network function of merging many input flows into a single output flow This requires formating the data and encoding side information about when messages start, what their lengths are and what their origins and destinations are This thesis examines efficient ways of performing these functions, the objective being to minimize the average message delay, or some other queueing theoretic quantity, like the probability of buffer overflow The work is divided in four parts; (1) encoding of the data; (2) encoding of message lengths; (3) encoding of message starting times; (4) encoding of message origins and destinations With respect to data encoding, an algorithm is given to construct a prefix condition code that minimizes the probability of buffer overflow Next a theory of variable length flags is developed and applied to the encoding of message lengths For concentrators with synchronous output streams, it is shown that the concept of average number of protocol bits per message is meaningless Thus, in order to analyze the encoding of message starting times, a class of flag strategies is considered in which there is a tradeoff between delay and low priority traffic

Source coding for communication concentrators

A fallback strategy for a system (700) and method (200) is provided for rerouting a call that fails to be established utilizing a first set of constraints in a communication network system. This strategy enables the communication network system to utilize a look-around-first type of preemption that avoids unnecessary preemption and provides alternate routing for a call according to predetermined constraints selected by a user.

System and method for call-by-call source routing with rule-based fallbacks

Data flow in a communications network is controlled by a downstream node specifying the maximum average speeds of a plurality of data streams sent from an upstream node on a plurality of data paths.

Pierre A. Humblet

Papers

Communication system for sending an identical routing tree to all connected nodes to establish a shortest route and transmitting messages thereafter

Source coding for communication concentrators

System and method for call-by-call source routing with rule-based fallbacks

Network data flow control technique

Determinism minimizes waiting time in queues