# A Novel Approach for Improving XML Querying over Wireless Broadcast Channels
## 4 Analysis
### Concern Parameter's Description  
1. Partitioning the XML data stream: The time required to partition an XML data stream is determined by the partitioning criteria and the data stream's size and complexity. In general, partitioning takes linear time, so the access time can be estimated as O (n), where n is the size of the XML data stream. 2. Assigning partitions to wireless broadcast channels: The time required for this step varies according to the number of wireless broadcast channels and the load-balancing algorithm used. In general, load balancing can be performed in either constant or logarithmic time, so access time can be estimated as O (log n) or O (1), where n is the number of wireless broadcast channels. 3. Broadcasting XML data partitions: The time required to broadcast the XML data partitions varies according to network bandwidth and partition size. Broadcastingis typically performed in linear time, so the access time can be estimated as O (m), where m is the total size of the XML data partitions. 4. Query routing mechanism: 1. _Query decomposition:_ The time required for query decomposition varies according to the complexity of the query and the number of partitions involved. In general, query decomposition can take either linear or logarithmic time, so access time can be estimated as O (k log n) or O (k), where k is the number of partitions involved. 2. _Query caching:_ The time required for query caching is determined by the cache lookup time and network latency. If the query and its results are already cached, the estimated access time is O (1). If the query is not cached, the access time can be calculated as O (log n) or O (1), depending on the query routing algorithm used. 3. _Query broadcasting:_ The time required to broadcast a query is determined by the network bandwidth and the query's size. In general, broadcasting can be performed in linear time, so the access time can be estimated as O (p), where p is the query size. 4. Combining query results: The time required to combine query results is determined by the number of partitions used and the complexity of the result aggregation algorithm. In general, result aggregation can take either linear or logarithmic time, so access time can be estimated as O (k log n) or O (k), where k is the number of partitions involved. 5. Returning query results: The time required to return query results is determined by the network latency and the size of the result set. Returning results typically takes linear time, so the access time can be estimated as O (r), where r is the size of the result set. It is important to take into account data partitioning, load balancing, query routing, and network conditions when determining the access time for XML querying over wireless broadcast channels. To calculate access time, we can use a general equation that accounts for these factors. Access time (\(T_{access}\)) can be expressed as  
\[T_{access}=T_{partition}+T_{transmission}+T_{routing}+T_{processing} \tag{1}\]  
where  
* \(T_{partition}\) is the time required to partition the XML data stream. * \(T_{transmission}\) is the time needed to transmit the data over the wireless broadcast channels. * \(T_{routing}\) is the time taken to route the query to the appropriate channel(s). * \(T_{processing}\) is the time required to process the query and retrieve the relevant data. These parameters are further defined as
* _Partitioning Time (\(T_{partition}\))_ This is the time taken to divide the XML data into partitions. It depends on the size and complexity of the XML document and can be influenced by the partitioning algorithm used. \[T_{partition}=f\ (size_{xml},\textit{complexity}_{xml})\] (2)
* _Transmission Time (\(T_{transmission}\))_ This is the time it takes to transmit the data over the wireless channels. It depends on the size of the data partition, the bandwidth of the channel, and the number of channels.