Lack of symmetry, i.e. lack of balance or proportion. 1. In telecommunications, a link that supports more bandwidth in one direction than another. Asymmetric digital subscriber line (ADSL), for example, supports more bandwidth downstream than upstream. Bluetooth supports an asynchronous data channel that can operate in asymmetric mode at up to 721 kbps in either direction and 57.6 kbps in the reverse direction.Alternatively, the Bluetooth data channel can operate in symmetric mode at speeds of up to 432.6 kbps. See also ADSL, asynchronous, bandwidth, Bluetooth, channel, downstream, symmetric, and upstream. 2. In compression, a process that is not equally time-consuming and processor-intensive in terms of compression and decompression. See also compression.