SSE2

SSE2, Streaming SIMD Extensions 2, is one of the Intel SIMD (Single Instruction, Multiple Data) processor supplementary instruction sets first introduced by Intel with the initial version of the Pentium 4 in 2001. It extends the earlier SSE instruction set, and is intended to fully replace MMX. Intel extended SSE2 to create SSE3 in 2004. SSE2 added 144 new instructions to SSE, which has 70 instructions. Competing chip-maker AMD added support for SSE2 with the introduction of their Opteron and Athlon 64 ranges of AMD64 64-bit CPUs in 2003.

Features

Most of the SSE2 instructions implement the integer vector operations also found in MMX. They use the XMM registers instead of the MMX registers, which are wider and allow for significant performance improvements in specialized applications. Another advantage of replacing MMX with SSE2 is avoiding the mode switching penalty for issuing x87 instructions present in MMX because it is sharing register space with the x87 FPU. The SSE2 also complements the floating-point vector operations of the SSE instruction set by adding support for the double precision data type.

Service set (802.11 network)

In computer networking, a service set is a set consisting of all the devices associated with a consumer or enterprise IEEE 802.11 wireless local area network (WLAN). The service set can be local, independent, extended or mesh.

Service sets have an associated identifier, the Service Set Identifier (SSID), which consists of 32 octets that frequently contains a human readable identifier of the network.

Basic service set

The basic service set (BSS) provides the basic building-block of an 802.11 wireless LAN. In infrastructure mode, a single access point (AP) together with all associated stations (STAs) is called a BSS; not to be confused with the coverage of an access point, known as the basic service area (BSA). The access point acts as a master to control the stations within that BSS; the simplest BSS consists of one access point and one station.

The IEEE 802.11s amendment defined an additional protocol for wireless mesh networks. Only mesh STAs participate in mesh functionalities such as formation of the mesh BSS, path selection, and forwarding. Accordingly, a mesh STA is not a member of an IBSS (independent BSS) or of an infrastructure BSS. Consequently, mesh STAs do not communicate with nonmesh STAs. However, instead of existing independently, an MBSS can interconnect with other BSSs through the DS (Distribution System). Mesh STAs can communicate with nonmesh STAs through a logical architectural component called a Mesh Gate.