A protocol that controls power levels in an IEEE 802.11a wireless LAN (WLAN). Because 802.11a competes for spectrum with HiperLAN, the standard developed and promoted by the European Telecommunications Standards Institute (ETSI), 802.11a implementations in Europe must use TPC and dynamic frequency shifting (DFS), which dynamically shifts frequency channels. In combination, these protocols serve to eliminate interference issues with incumbent signals. See also 802.11a, channel, ETSI, frequency, HiperLAN/1, IEEE, interference, protocol, and WLAN.
(Transaction Processing Performance Council, San Francisco, CA, www.tpc.org) An organization devoted to benchmarking transaction processing systems. In order to derive the number of transactions that can be processed in a given time frame, TPC benchmarks measure the total performance of the system, which includes the computer, operating system, database management system and any other related components involved in the transaction processing operation. Transactions The TPC-C benchmark yields transactions per minutes expressed in tpmC ratings. Earlier TPC-A and TPC-B benchmarks produced tpsA and tpsB ratings, which measured transactions per second. TPC-W is a Web benchmark, performed in a controlled Internet e-commerce scenario and reported as the number of Web interactions processed per second. Shopping, browsing and ordering are the three simulated profiles measured. Database Queries TPC-H carries an ad-hoc label and is used in environments where users do not know which queries will be executed against a database system. TPC-R analysis assumes pre-knowledge of a standard set of queries, and execution is very fast as a result. The earlier TPC-D benchmark based its results on the size of the database being queried and yielded a single-user Qppd Power metric and multiple-user QthD Throughput metric.