Wireless link control protocol(RLC)

RLC definition

Wireless link control protocol RLC layer located above the MAC layer, for users and control data provide segment and retransmission business. Each RLC entity by RRC configuration, and according to the business types have three modes: transparent mode (TM), the confirmation mode (UM), the confirmation mode (AM). In the control plane, to provide business RLC upper for wireless signaling bearing (sulfate-reducing bacteria); The user plane, when PDCP and were not the business BMC agreement when using, RLC to provide wireless bearing (upper); RB Otherwise the RB business by PDCP or BMC bearing.

Edit this paragraph RLC three models of actual operation

As follows:

* transparent mode: send entity in high-rise data does not add any additional control protocol expenses, only according to business types deciding whether to proceed with multistage operation. Receiving entity receiving units = pdus incorrectly, the configuration, in the wrong mark after submitting or directly discarded and to top report. Real-time speech business usually adopts RLC transparent mode.

* not confirm mode: send entity in high-rise units = pdus add the necessary control protocol expenses, and then transmit but is not guaranteed transmission to peer entities, and no use retransmission agreement. Receiving entity to receive data errors marker for error after submitting, or directly discarded and to top report. Because RLC units = pdus contains external, so that can detect high-rise units = pdus integrity. UM mode in the business community radio and IP telephone.

* confirm mode: sending side in high-rise data add the necessary control protocol overhead transmission, and ensure after passing to peer entities. Because have ARQ ability, if RLC receives wrong RLC units = pdus, notify the sender of RLC retransmitted the units = pdus. Because RLC units = pdus contained some external information to support data to top order/disorderly sequence submitted. AM mode is a packet data transmission standard model, such as the WWW and E-mail to download.

Executive function. Main RLC

Are: connection control.

 segmented/restructuring. The length of different top is to ask for units = pdus piecewise restructuring smaller RLC load units (PU);

 cascade. When a RLC sdus content not fill a complete RLC units = pdus may, when will the next RLC sdus of the first section on the PU, with the former one RLC sdus the last paragraph level together,

 filling. When RLC sdus content not fill a complete RLC units = pdus and unable to cascade when the rest of the space with the fill bits to fill,

 correcting. In confirmation mode through heavy spread correct mistakes,

 high-rise units = pdus order sent. According to senior units = pdus RLC submit down sequence to send. Mainly used for AM mode;

 flow control. By on the other side RLC receiver RLC sending end rate control;

 copy inspection. Check receives RLC units = pdus, and guarantee to top only submit one time.

 external examination. In UM mode, this function ensure units = pdus integrity. And in RLC units = pdus be restructured into RLC sdus, by examining the external units = pdus RLC provide a detection method of deteriorating RLC sdus,

 agreement error detection and recovery. Detection RLC agreement mistakes and recovery,

 encryption. In UM/AM mode, the data encryption. Please refer to the following relevant sections of specific content,

 pause/continue to function. Suspend or continue data transmission. They belong to the local operation, by RRC through control interface is controlled.

RLC can also mean by resistance R, inductance and capacitance C L, composed of circuit.

RLC can also mean with binary circular moves left.