Client Resources, Bandwidth, and Latency Summary

Copyright © 2012 Open Geospatial Consortium 51 GeoBox Metadata Node

18.3 Client Resources, Bandwidth, and Latency

The number of fielded sensors is constantly growing. For surveillance, reconnaissance and analytics applications, a web server may be required to field a large number of collections. These collections may be organized in a complex tree structure. The networks may be high bandwidth, but with high latency. They may not be high bandwidth either. The interface shall provide a way to send as much data as possible in a single request as well as allow the client to query the data in smaller chunks. The clients may not have enough computing resources such as memory to handle a large tree. For clients with limited resources, the basic method to follow would be to: 1. Get the number of nodes in the tree and its depth. In other words, get the number of total nodes, leaf nodes, and the depth of the tree. 2. Get the root node and traverse the tree one level at a time. 3. Get metadata on a per-collection basis. 4. Request for compressed XMLs to further save bandwidth. For clients with reasonable resources and high latency, minimize number of requests: 1. Get the number of nodes in the tree and its depth. In other words, get the number of total nodes, leaf nodes, and the depth of the tree. 2. Get the entire tree, with metadata. 3. Request for compressed XML to reduce incurred cost of bandwidth. 19 CS service model

19.1 Summary

A summary of all the requests for a collection service is specified in the table below: Table 15: Collection Service request summary Request Meaning Parameters Optionality GetCapabilities Allows the client to retrieve metadata about the capabilities of the CS server implementation Service, Request, Sections, AcceptVersions, AcceptFormats, AcceptLanguages, UpdateSequence, Mandatory GetHelp Allows the client to retrieve help on topics provided by the server Service, Request, Version, Topic, Format Optional GetCollectionCount Retrieves the number of collections being served by the server Service, Request, Version, Format, AcceptLanguages, NID, Depth, Bbox, CRS, Time Optional Copyright © 2012 Open Geospatial Consortium 52 GetCollections Retrieves the set of collections being served by the server. Optionally, metadata about each collection can also be retrieved. Basic filtering capabilities permit control over quantity of data transmitted. Service, Request, Version, Format, NID, Metadata, Depth, Bbox, CRS, Time Mandatory

19.2 Request UML XMLKVP