Seeking a position to solve challenging/interesting issues as a software developer in the fields of Telecommunication.Experienced in telecom system state machine oriented processing logic and wireless call processing and signalling. Function equally well as in individual and in a team environment both as a leader and as a member. I am a very experienced developer and I wrote software not only for my employer but also for myself to speed up my work. These tools also benefit many others in the development community of my employer.
Operating Systems: UNIX, Linux, Windows.
Software/Other: Call processing, SS7, SIP, TCP/IP, cgi
- make tandem/gateway co-exist on the same MMSI and configurable on a per channel group basis.
- Flexible Alerting feature with SIP protocol - flexible alerting is an existing CDMA feature that works on 5ESS.
- Given that we need to made this feature worked without changing either the ECP code or the PSG code and only changed the MMSI code while making it interface with SIP (instead of ISUP) as inter-office protocol.
- Call Hold feature with SIP protocol - Call Hold for SIP protocol is a bin challenging since the SIP hold model diverge from traditional Confidential hold model and need to inform far end switch to change the voice path.
- Plus I needed to undo a bound of patch work that has been done for the traditional Call Hold model.
- This work involved both CS and NGSS on a MMSI.
- CMS (aka WMS) basic call processing infrastructure work - porting/rewriting code from Confidential as base for CMS call processing.
- There are three layers of application: one interface with MGC h248 protocol, one interface and manipulate the bearer and I was doing the one bridge the previous two layers to make sure all incoming h248 requests are valid and divide up the requests into atomic operations and feed the operation to bearer layer in an orderly manner.
- This work provided the infrastructure for all the call processing feature finite state machines are based.
- I was part of the Confidential team designated to help them from the very beginning and contributed to achieve the first call in less than a year on a new platform.
- I setup the simulator testing environment which still is the predominant developer testing vehicle in use today.
- I did for Confidential .
- When a mobile device is dual registered on both 3G/4G network.
- Once the 4G radio coverage drops, 3G circuit switched call will take over and allows voice call to continue.
- Worked on various call processing/maintenance features of 5ESS project which including but not limited to PHS call processing, GSM call processing, 5ESS call processing, 5ESS terminal maintenance, diagnostic etc.