In computer networking and telecommunication, a frame is a digital data transmission

Data transmission

Data transmission, digital transmission, or digital communications is the physical transfer of data over a point-to-point or point-to-multipoint communication channel. Examples of such channels are copper wires, optical fibres, wireless communication channels, and storage media...

 unit or data packet that includes frame synchronization

Frame synchronization

While receiving a stream of framed data, frame synchronization is the process by which incoming frame alignment signals, i.e., distinctive bit sequences , are identified, i.e., distinguished from data bits, permitting the data bits within the frame to be extracted for decoding or retransmission...

, i.e. a sequence of bits or symbols making it possible for the receiver to detect the beginning and end of the packet in the stream of symbols or bits. If a receiver is connected to the system in the middle of a frame transmission, it ignores the data until it detects a new frame synchronization sequence.

In computer networking, a frame is a data packet on the Layer 2

Data link layer

The data link layer is layer 2 of the seven-layer OSI model of computer networking. It corresponds to, or is part of the link layer of the TCP/IP reference model....

 of the OSI model

OSI model

The Open Systems Interconnection model is a product of the Open Systems Interconnection effort at the International Organization for Standardization. It is a prescription of characterizing and standardizing the functions of a communications system in terms of abstraction layers. Similar...

. A frame is "the unit of transmission in a link layer protocol, and consists of a link-layer header followed by a packet." Examples are Ethernet frame

Ethernet frame

A data packet on an Ethernet link is called an Ethernet frame. A frame begins with Preamble and Start Frame Delimiter. Following which, each Ethernet frame continues with an Ethernet header featuring destination and source MAC addresses. The middle section of the frame is payload data including any...

s (maximum 1500 byte plus overhead), PPP

Point-to-Point Protocol

In networking, the Point-to-Point Protocol is a data link protocol commonly used in establishing a direct connection between two networking nodes...

 frames and V.42 modem frames.

In telecommunications, specifically time-division multiplex (TDM) and time-division multiple access (TDMA), a frame is a cyclically repeated data block that consists of a fixed number of time slots, one for each logical TDM channel or TDMA transmitter. In this consist, a frame is typically an entity at the physical layer. TDM application examples are SONET/SDH and the ISDN circuit switched B-channel. TDMA examples are the 2G

2G

2G is short for second-generation wireless telephone technology. Second generation 2G cellular telecom networks were commercially launched on the GSM standard in Finland by Radiolinja in 1991...

 and 3G circuit switched cellular voice services. The frame is also an entity for time-division duplex, where the mobile terminal may transmit during some timeslots and receive during others.

See also

• Data Link Layer
  Data link layer
  The data link layer is layer 2 of the seven-layer OSI model of computer networking. It corresponds to, or is part of the link layer of the TCP/IP reference model....
  
  
• Multiplex techniques
  Multiplexing
  The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...
  
  
• Overhead bit
  Overhead bit
  In data transmission and telecommunication, overhead bits are nondata bits necessary for transmission .Such bits are not counted as part of the goodput....
  
  
• Packet (information technology)
• Protocol data unit
  Protocol data unit
  In telecommunications, the term protocol data unit has the following meanings:#Information that is delivered as a unit among peer entities of a network and that may contain control information, address information, or data....
  
  
• Jumbo frame