The General Packet Radio Service (GPRS) Logical Link Control (LLC) protocol transfers packet data between the Mobile Station (MS) and Serving GPRS Support Node (SGSN). LLC provides logical links between an MS and SGSN using the services of the Radio Link Control/Media Access Control (RLC/MAC). An SGSN uses LLC to provide logical links to the MSs within its area. LLC provides services to the SubNetwork-Dependent Convergence Protocol (SNDCP), GPRS Mobility Management (GMM), Session Management (SM) and Short Message Service (SMS) protocols.

LLC provides the following basic capabilities:

  • Acknowledged and unacknowledged information transfer
  • Flow control in an Asynchronous Balanced Mode (ABM) operation
  • Frame error detection

Trillium LLC software enables telecom equipment manufacturers of soft switches, signaling gateways, signal transfer points, service control points, media gateway controllers or other products to:

  • Accelerate time to market
  • Reduce development costs
  • Reduce project risk of internally developed LLC applications

Product deliverables consist of C source software, documentation, training, a warranty and technical support.

FEATURES + BENEFITS

  • Supports the operation of a single SGSN toward multiple MSs.
  • One instance provides services to multiple upper layer entities within an MS or SGSN.
  • Provides one or more logical link connection(s) between an MS and SGSN. The SAPI discriminates the multiple links between an MS and SGSN.
  • Maintains a sequential order of frames across a logical link for an acknowledged operation.
  • Detects transmitting, formatting, and operating errors on a logical link.
  • Buffers frames when a BSSGP or an RLC/MAC reports congestion for an acknowledged operation.
  • Provides flow control in the ABM.
  • Negotiates and renegotiates the LLC layer and upper layer parameters.
  • Transfers frames based on the precedence class for an ABM.
  • Receives the uplink traffic at the SGSN from multiple instances of BSSGP; receives the downlink traffic at the SGSN from multiple instances of SNDCP.
  • Distributes the uplink traffic at the SGSN to multiple instances of SNDCP; distributes the downlink traffic at the SGSN to multiple instances of BSSGP.
  • Transfers unacknowledged and acknowledged information.
  • Recovers from detected errors.
  • Notifies unrecoverable errors.
  • Negotiates XID.
  • Transfers prioritized data.
  • Conforms to Trillium Advanced Portability Architecture (TAPA)
  • Benefits of licensing Trillium software from Continuous Computing

PRODUCT INTERWORKING

Trillium LLC software interworks with Trillium BSSGP, Trillium SNDCP and Trillium GMM/SM software products.

CONFORMANCE

Trillium LLC software conforms to the following standards:

  • GSM 04.64, release 1998, “Digital Cellular Telecommunication System (Phase 2+); General Packet Radio Service (GPRS); Mobile Station – Serving GPRS Support Node (MS-SGSN) Logical Link Control (LLC) Layer Specification.”
  • GSM 04.65, release 1998, “Digital Cellular Telecommunication System (Phase 2+); General Packet Radio Service (GPRS); SubNetwork-Dependent Convergence Protocol (SNDCP).”
  • GSM 08.18, release 1998, “Digital Cellular Telecommunication System (Phase 2+); General Packet Radio Service (GPRS); Base Station System (BSS) – Serving GPRS Support Node (SGSN); BSS GPRS Protocol (BSSGP).”