Grace Ding

 

8204 Spring Valley Lane, Plano, TX 75025

(972) 379 8809

xdingtx75@yahoo.com

www.linkedin.com/in/graceding1

 

        NFV / VoLTE IMS / SIP / Packet Core Engineers

 

SUMMARY

 

Telecommunication System Test Engineer with over 15 years of system integration and verification experience in voice and data communication technologies. Extensive experience with system integration execution including test analysis, test descriptions, equipment booking, network element connectivity and configurations. Knowledge of SDN and NFV architectures and technologies. In-depth knowledge of GSM, LTE and VoLTE/IMS network architectures, protocols and call processes. Solid technical expertise in intelligent network (IN) value-added services and customer adaptations for GSM and VoLTE/IMS core networks. Experience in voice and data traffic simulation, test automation, software development, function test, system integration test, load test, performance test, deployment and support on leading-edge telecommunication products. Successfully delivered IN solutions to domestic and international operators. Strong analysis and troubleshooting skills. Thrive on challenges. Demonstrated strengths include:

 

* System Integration and Verification

* Quality Assurance

* Test Automation

* Software Testing

* Value-Added Services & Customer Adaptation

* Requirement Analysis

* Test Strategy and Planning

* Technical Configuration Management

* Leadership and Team Development

 

 

TECHNICAL SKILLS

 

Communication Protocols: Diameter, SIP, H.248, SDP, GTPv2, GTP-U, S1AP, SGsAP, RTP, CS1+, CAP v2, SCAP v2, MAP, TCAP, ISUP, SS7, TCP/IP, CIP/IP, CIP/SS7, SIGTRAN

Programming Languages: TTCN-3, C/C++

Operating Systems: SUN Solaris, Linux, Dicos

Database Management:  TimesTen (In-Memory Database)

Communication Solutions: Wireless Priority Service, Prepaid & Real-time Charging System, Answer Tone & Ring2U Enriched Voice, Mobile Virtual Private Network, EBI Web Care, Billing Gateway, Service Order Gateway, ISDN Access Node.

Telecommunication standards: ANSI, ITU, 3GPP

Testing tools: Protocol Analyzers (GeoProbe/G10, AcceSS7, Wireshark, AXE Protocol Analyzer), Traffic Generators (Jmeter, LoadRunner, MGTS, NetHawk EAST, scripts), Netcool, Shunra

 

 

PROFESSIONAL EXPERIENCE

 

Advanced Mobile Integration, Richardson, Texas                         2014 – 2015

Network Engineer / CTAC Operations at AT&T Mobility

- Performed end-to-end testing of VoLTE network deployment in identified markets. Verified VoLTE telephony voice services, E911, Inter-RAT (Radio Access Technology) handover, Intra-system handover such as SRVCC (Single Radio Voice Call Continuity) features in operator’s LTE/EPC/IMS production networks. Troubleshooting of complex issues including all technologies, signaling protocols, and major network elements.

- Executed end-to-end testing of LTE network deployment. Verified LTE voice and data call flows and QoS (Quality of Service).

- Performed Prepaid IVR (Interactive Voice Response) system test.

- Supported MME (Mobility Management Entity) acceptance test.       

 

ERICSSON INC, Plano, Texas                                           1996 - 2013

Test Lead / Senior System Integrator / Senior Software Engineer (2007 – 2013)

- Adapted GSM Charging System solution to VolTE/IMS AT&T network. Performed validation in the QA lab. Coded TTCN-3 test scripts to prototype testing VoIP between TAS (Telephony Application Server) and CCN (Charging Control Node). Verified online charging and call flows involving SIP, Diameter, H.248 (Media Gateway Control Protocol), SDP (Session Description Protocol), and IMS charging context. Wireshark was used in the test to analyze packet data and network protocols.

 

- In the BSS/IN automation project, developed and debugged TTCN-3 scripts to automate CAPv2 voice, SCAPv2 messaging, data and content traffic from circuit-switched and packet-switched networks.

 

- Performed function tests of web-based applications for account management, including the Customer Care provided for AT&T customer service representatives, the Self Care for AT&T subscribers, and the Reseller Customer Care for MVNOs that resell AT&T network services under their own brand. Also, verified EBI (Enhanced Bi-directional Interface) database and EBI interfaces offered by Ericsson Charging System EBI solution.

 

- Migrated Charging System solution from AXE based SCP-T to TSP (Telecom Server Platform) for AT&T. Performed regression test of AT&T specific customizations over CIP/SS7 and CIP/IP interfaces. Verified real-time charging, billing, service provisioning, roaming, announcements, statistics, and fault management. Performed interoperability test with multi-vendor MSCs. 

 

- Led a verification team in hosted shared Prepaid project based in Plano for international multi-tenants. Integrated and verified the managed service with Vodafone Netherland & Ztar Singapore core networks.

 

- Verified Charging System SDP geo-redundancy replication solution for T-Mobile. Setup replication between the cluster SDP (Service Data Point for Charging System) and the redundancy server SDP. Verified GeoDiv replication scripts with Voice-106 feature enabled, high traffic load and network latency. Sigtran, NetHawk EAST, and Shunra were used in the test.

 

- Performed NIT of Voice-106 account management with shared balances and service limits for T-Mobile, and regression tested all the existing T-Mobile customizations.

 

 

Solution Architect / Senior System Integrator / Senior Software Engineer  (2001 – 2006)

- Uplifted SCP AXE IN services to the Intelligent Network Server (INS) on the TSP (Telecom Server Platform) for T-Mobile. Performed NIT and load test of T-Mobile specific Prepaid customizations, including PSL (Prepaid Service Logic), RING2U, and StarEasy. HSSL (High Speed Signaling Link) & SS7 (low speed) links, and NetHawk EAST (Environment for Automated System Test) were used in the test.

 

- Answer Tone solution was an innovative value-added service which was designed, verified, deployed and supported by experts from our local team. In the managed Answer Tone service delivery for AT&T, installed and verified Prepaid and Postpaid Answer Tone solutions on AXE based SCP-T with patches in AXE SSFAM and SCFAM for call handling. Tested 3PP with Comverse engineers for content management, web provisioning, and Fundial IP player features. Performed interoperability test with multi-vendor MSCs (Ericsson, Nortel, Nokia, and Lucent). Improved test tools to assist in ETC (Establish Temporary Connection) troubleshoot and led to higher ETC success rate. Migrated Answer Tone service to the TSP (Telecom Server Platform). Performed TSP upgrade and 2nd line support. Received recognition award from the line manager for outstanding performance.

 

- Performed NIT of Prepaid Nationwide solution for T-Mobile and verified T-Mobile customizations.

 

- Performed solution investigation for customer’s change requests. Developed technical report, design cost and lead-time estimation.

 

- Led a function test team and verified Ericsson Prepaid SDP (Service Data Point for Prepaid) and SCP (Service Control Point for Prepaid) products and tools for R&D organization.

 

System Integrator / Software Engineer (1996 – 2000)

- Coordinated WAP Gateway integration test and WAP trial for Powertel.

- Performed service upgrade in operator’s production system to ensure that the Prepaid system was Y2K compliant. Provided remote support to RTACs (Powertel, Omnipoint, and Sprint).

- As part of the rollout plan, performed regression test of IN services with the latest MSC and CSS software release for Pacific Bell Wireless (now AT&T) on site.

- Performed product line management (PLM) for the IN 6.1 Platform Consolidation Project. Updated and maintained test dumps to the latest ACA level. Created and maintained Software Records Database to facilitate PLM coordination among the design and verification organizations.

- Integrated SEMA AUC/EIR with Ericsson core network. Verified equipment (e.g. SIM card and handset IMEI) management features of the SEMA Authentication Center (AUC) and Equipment Identity Register (EIR).

- Performed Mobile Virtual Private Network (MVPN) installation and acceptance test for Pacific Bell Wireless (now AT&T) on site.  Worked with customer face-to-face and gained great trust with the customer. Successfully deployed the Ericsson MVPN, the First Of Application (FOA), in the operator network and won the contract. Received Ericsson special achievement recognition award from the key account managers and project manager.

- Performed all aspects of installation, commissioning and support of Prepaid solution for Sprint on site. Successfully deployed the Ericsson PPS, the First Of Application (FOA), in North America.

- Performed beyond expectation in the handling of MXE-BGw (Billing Gateway) integration test and the BGw primary consolidation for GSM CMS 40 core network. Integrated BGw with MXE, MSC and OSS. Verified Call Data Records (CDR) billing processing features. Checked fault management in the OSS. Acted as the main interface to the EMX organization for the BGw-MXE issues and successfully contributed to resolving problems. Received Ericsson special achievement recognition award from the department manager.

 

- Integrated the Service Order Gateway (SOG) with EIR, AUC, HLR and OSS. Verified SOG interfaces towards network elements. Checked fault management in the OSS.

- Integrated the ISDN Access node (BITBOSS 2400), a 3rd party product from Eastern Independent Telecom (EIT), with MSC and PBX. Verified protocol conversion between the PSTN/ISDN and call handling. In the integration test and primary consolidation phase, persistently sought resolution to the problems. Enabled Powertel and Ericsson to successfully deploy this feature in the operator’s network. Received Ericsson special achievement recognition award from the department manager.

 

 

EDUCATION

 

Master of Computer Science, University of Texas at Arlington, Arlington, Texas, USA.

Master of Electronic Engineering, Huazhong University of Science and Technology, P. R. China.

 

 

PERFORMANCE AWARDS

 

1996 Ericsson Special Achievement Recognition, BGw Delivery for Pacific Bell Mobile Service (now AT&T)

1997 Ericsson Special Achievement Recognition, ISDN Access Node Delivery for Powertel

1999 Ericsson Special Achievement Recognition, MVPN Delivery for Pacific Bell Wireless (now AT&T) 

 

US citizen