Operation and Support Subsystem
• OSS consists of two entities not fully specified
in GSM. They are
– Operation and Maintenance Center (OMC)
– Network Management Center (NMC)
• Performs alarm handling, fault management,
performance management, configuration
management, traffic data acquisition, activate
and deactivate functions, and long term
• Normally centralized in a network.
• A-Interface ---- between BSC and MSC, E1 link.
• Abis-Interface ---- between BTS and BSC using LADP
(Link Access Data Protocol) protocol.
• B-Interface ---- between MSC and VLR
• C-Interface ---- between MSC and HLR
• D-Interface ---- between HLR and VLR
• E-Interface ---- between MSCs
• F-Interface ---- between MSC and EIR
• Um-Interface ---- between MSS and BSS.
Questions & Answers