T1 and E1 are related to Telecommunications and Telecom: A Global Communication Standard.

The E1 link or circuit is the most commonly used format within the E carrier system.E1 circuits are used for connecting a variety of elements within a network.The E-carrier standards form part of the Synchronous Digital Hierarchy scheme.Groups of E1 circuits containing 30 circuits can be combined to produce higher capacity.There are carriers in increasing multiples of the E1 format.The E3 can carry 480 circuits and has an overall capacity of 34.368 Mbps.The E1 and E3 lines are both transmitted as many times as possible.Unlike internet data services which are internet based, E-carrier systems are circuit switched and allocate capacity for a voice call for its entire duration.This ensures high call quality because the transmission arrives with the same delay and capacity at all times.packet switched data systems offer the same flexibility and efficiency as circuit switched lines.Different applications use different capacities of E1 and E3 links.Medium and large companies use E1 circuits to connect to telephone exchanges.Links between some exchanges may be provided by them.Where higher capacity is needed, E3 lines are used.They are often installed to connect countries.The E1 link runs over two sets of wires that are normally coaxial cable and the signal itself comprises a nominal 2.4 watt signal.The signalling data rate is full duplex and provides both directions.There is a frame that has been used.A frame of 32 time slots of octets is provided by the E1 frame format.There are 8 bits which are numbered 0 to 31.The name of the game is Time Slot.8000 Hz is the frame repetition rate.This E1 frame time slot is used for synchronisation, alarms and messages.It is reserved for the purpose of framing.The receiver can lock onto the start of each frame and match up each channel in turn.The standards allow for a full Cyclic Redundancy Check to be performed.The time slots are used for user data.Control, call setup and teardown are included.Channel Associated Signalling (CAS) is a protocol used to replicate opening and closing of a circuit.Tone signalling can be used on the voice circuits.Common Channel Signalling (CCS) is used by more recent systems to send short messages with call information.Data may be carried on this time slot.The E1 frame times slots are used for carrying user data.HDB3 is used almost exclusively.The next page deals with wireless and wired communication basics.

The E carrier system uses the E1 link or circuit as the most common format.E1 circuits are used for connecting a variety of elements within a network.

The E-carrier standards are part of the scheme.Groups of E1 circuits containing 30 circuits can be combined to produce higher capacity.There are carriers in increasing multiples of the E1 format.The E3 can carry 480 circuits and has an overall capacity of 34.368 Mbps.

The E1 and E3 lines are both transmitted as many times as possible.Unlike internet data services which are internet based, E-carrier systems are circuit switched and allocate capacity for a voice call for its entire duration.This ensures high call quality because the transmission arrives with the same delay and capacity at all times.packet switched data systems offer the same flexibility and efficiency as circuit switched lines.

Different applications use different capacities of E1 and E3 links.Medium and large companies use E1 circuits to connect to telephone exchanges.Links between some exchanges may be provided by them.Where higher capacity is needed, E3 lines are used.They are often installed to connect countries.

The E1 line runs over two sets of wires that are normally coaxial cable and the signal is a nominal 2.4 watt.The signalling data rate is full duplex and provides both directions.

There is a frame that has been used.A frame of 32 time slots of octets is provided by the E1 frame format.There are 8 bits which are numbered 0 to 31.The name of the game is Time Slot.8000 Hz is the frame repetition rate.