Abstract: Method and system for a distributed navigation system. The system comprises a client integrated with a mobile communication device (e.g. PDA, cellular telephone, etc.) and a server communicating via wireless carriers and the Internet. In one embodiment, the server obtains a user's initial position, a user-designated destination, and calculates a nominal route from the user's initial position to the destination. If a deviation from the nominal route is detected, the reroute tasks are divided between the server and the client according to a corridor area surrounding the nominal route. Mapping information related to the corridor area is stored in the client, and the amount of the stored mapping information depends on the storage and/or processing capabilities of the client.

Abstract: Method and system for prediction-based navigation in a real-time distributed navigation system. In one embodiment, a server receives a request from a client comprising one or more position coordinates. The server estimates the user's speed, estimates total elapsed time, calculates an optimal route to the destination and sends a set of routing directions to the client. Moreover, the server estimates a route origin within an estimated comfort zone in order to calculate the optimal route from the estimated origin to the destination.

Abstract: A data compression process and system that identifies the data type of an input data stream and then selects in response to the identified data type at least one data compression method from a set of data compression methods that provides an optimal compression ratio for that particular data type, thus maximizing the compression ratio for that input data stream. Moreover, the data compression process also provides means to alter the rate of compression during data compression for added flexibility and data compression efficiency. Furthermore, a system memory allocation process is also provided to allow system or user control over the amount of system memory to be allocated for the memory intensive data compression process. System memory allocation process estimates the memory requirement to compress the input data stream, and allocates only that amount of system memory as needed by the data compression for memory allocation efficiency.