Device to Device Communication


  • Device to Device Communication has been the latest reasearch topic for LTE advanced. Which enables UE's those are in the proximity to discover and communicate with each other.
  • Various use cases involved are
    • Social gaming
    • Commercial advertisements
    • Pubic safety purposes
    • Network offloading  
  • Enormous operator benefits involved using device to device communications such as
    • Peak data rates: as the UE's are near by due to which good radio conditions can enables higher modulation schemes.
    • Low latency: No need to go through all the network entities involved in data communication.
    • Capacity: Due to spectrum re use UE can accommodate more users
    • Extended Coverage : UE's in network coverage can provide services to UE's which are present out side of network coverage (Relay operation)
  • With the advancement in the technology and social life opened new ways to communication.
  • Prose is a feature that enables operator network controlled discovery and communications between UEs that are in proximity.
  • It allows UE's in proximity will discover other UE's in their vicinity and start communication directly with less involvement of network.
  • Various use cases involved such as location based advertising (Ads by shops to customers passing near by), social networking applications (facebook, twitter),network off loading and Public safety etc.
  • The communication path could for example be established directly between the UEs or routed via local eNB(s).
Discovery Types : 
  • Open ProSe Discovery: is ProSe Discovery without explicit permission from the UE being discovered.
  • Restricted ProSe Discovery: is ProSe Discovery that only takes place with explicit permission from the UE being discovered. UE's can have a feature enabled whether it can be discovered by other UE's are not (privacy).
  • Operator can change dynamically the range of the proximity per user/application. 
Disovery Models :

Model A:
  • Model A is push model like "i am here". used for both open and restricted discovery.
Model B:
  • Model B is pull model like "who are there" or "Are you there". it is used for restricted discovery. 







3GPP TR 22.803,3GPP TS 23.303