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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
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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