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LAPD Module


The LAPD module allows to open up to 256 physical LAPD links, and each physical LAPD supports up to 128 logical links. It supports either user or network operation mode. The client refers to the standard DL-* set of primitives for communication between layer 3 and the data link layer.
This function supports multiple protocol istances addressed to different client. The client works with standard primitives at the third protocol layer.(DL_ESTABLISH, DL-RELEASE, DL-DATA, DL-UNIT DATA). 

Functional description

Main features:

  • Several clients can work in concurrent maner.
  • A single client can activate multiple physical links.
  • Every LAPD instance supports multiple logic links.
  • Both User and Network operation manner.
  • Up to 256 LAPD istances supported.
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Satellite Delay Module

Functional description

The Satellite Delay module allows to simulate delay due to transmission path through satellite. The function works with channels of any rate, corresponding to a variable set of timeslot of the PCM lines. The user can specify the required delay in the range (10 ms – 4 s). The LSU+ is able to apply delay up to the full bandwidth of the incoming PCM flow.
 
 


 

LSU+ allows to delay up to 8 data flows (4 if they are bidirectional).
 
 
 
 
 
 
 

The byte stream flows through an octect queue dimensioned appropriately.
 
 
 
 
 
 
 
 
 
 
 
 

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SS7 Module

Functional description

The LSU+ protocol stack consists of MTP and SCCP protocol layers, that allow to implement a signalling point within an SS7 network, while the client manages the upper protocol layers. The MTP supports a multiple link-set associated to the signalling point, and it manages the signalling transfer function among them. The SCCP implementation includes the “Basic connectionless class”, the “Sequenced connectionless class” and the “Basic connection-oriented class”. A suite of SAPs allows to operate at different protocol levels, with the possibility to disable the upper ones, or to modify the basic behaviour. The special O&M SAP allows to configure the protocol stack and the routing tables.
Main features.

  • Several clients can work in concurrent manner.
  • A single client can activate set of multiple links.
  • Up to 256 physical links supported.
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Trau Frames Module

Functional description

TRAU Frame Uplink <-> Downlink single channel loop back
 

TRAU Frame Uplink <-> Downlink dual channel cross loop

The Trau Frames module allows to close the loop between uplink and downlink flow of TRAU frames (GSM 08.60) of GSM speech channels. It can operate either against TRAU or against BTS. As the frame format in the two opposite directions is not symmetrical, LSU+ processes the data-flow in real-time in order to adjust it; then it handles time alignment procedure in either BTS or TRAU mode. Cross switch of frame flow between two different channels is also supported. The function works with up to 256 channels in parallel.
Main features:

  • The time allignment modality for BTS and TRAU is supported.
  • Loop of speech or data frames.
  • Concurrent functions up to 256 channels.
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V.110 Module

V.110 Monitor & HSCSD De-multiplexer — The V.110 Monitor is a special function designed to analyse the data flow through the A-interface channels when they are used for HSCSD data service, that consists of one or multiple parallel substreams of V.110 data frames. The package includes a function for scanning all the timeslots of a suite of PCM lines in order to identify all channels that are operating with V.110 data frames. A post processing utility allows to verify the synchronisation among the HSCSD sub-streams.
It also manages the particular frame allignment of GSM data channels for the A interface, where the main data stream is distributed into multiple substreams which work at 8 or 16 Kb/s. This module also includes a special function that allows to scan all the timeslots in a suite of PCM lines to identify all the channels working with the V.110 frame.

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More modules

Info: lsu@prisma-eng.it