Evaluation of Project 25 Inter-RF Subsystem Interface Behavior
There is a need for evaluating the performance of the P25 Inter-RF Subsystem Interface (ISSI) system in order to gain insights on the overall system performance including the audio quality and latency in set-up. As more testing and demonstration events are planned for testing ISSI prototypes and products, a simulation tool that models the behavior of the ISSI system may come in handy for planning these experiments, but also providing additional feedback on the system performance for various deployment configurations, parameters, and as ISSI is interfaced with other technologies. This is especially true for large deployment topologies where experimental set-ups and demonstrations may be too costly to realize.
Our objective is to help users gain insights on how the ISSI interface works, which should permit the users to simulate various deployment configurations and parameter settings without the need for procuring and setting up expensive testbeds and demonstrations.
We are developing a model for the ISSI as an extension to the NS-2 simulation platform. Our model includes the call control manager, mobility manager, and transmission control manager as specified in TIA-102.BACA as well as extensions to existing NS-2 Session Initiation Protocol (SIP) models.
A sample screen capture of the Graphical User Interface (GUI)
A sample ISSI protocol message exchange between two subscriber units (SU)
Emerging and Mobile Network Technologies Group