Continuing technology development of the software-defined RAN we pioneered by Range Networks (acquired by Africa Mobile Networks). AMN selected Range as the basis for the development of its own in-house Radio Access Network (RAN) solution, because of Range's highly innovative software-based solution which supports both multi-carrier and multi RAT (2G, 3G, 4G Radio Access Technology) with a single radio node.AMN builds, owns, operates and maintains mobile network infrastructure, delivering services for the biggest Mobile Network Operators (MNOs) in Africa. AMN's Network-as-a-Service (NaaS) model allows Africa's tier-1 Operators to expand their network coverage, deep into rural areas, with no capex investment and no opex risk. The first AMN production (12 metre monopole) sites based on the new Range-based RAN equipment are expected to be deployed from mid 2021. These sites will have a base configuration of 3TRX (2G) with HSPA (3G) in the 900MHz GSM band, upgradeable to 8TRX (2G) with HSPA (3G) and LTE (4G). The 20m self-supporting lattice towers will offer 9TRX plus 3x HSPA and LTE carriers in 3 sectors each for 2 co-located operators. Additional frequency bands will also be supported.

Doing anything and everything from a technical standpoint to commercialize OpenBTS into a complete, deployable cellular solution. More specifically, extensive design and software development at layers 1-4 (PHY, MAC, RLC, RRC, NAS, SGSN/GGSN, MSC/HLR/SMSC, RRLP) of a carrier-grade 2.75G and 3G software-defined mobile network. Successfully deployed and performing well in numerous environments for numerous customers. Also currently developing 4G/LTE network in a similar fashion. With a robust software-based solution, we can fundamentally change the equation. Range Networks’ software runs on inexpensive, off-the-shelf hardware (typically at less than 20% of the cost of custom hardware) to deliver full-featured mobile services, allowing the operator to make a profit while charging a price that almost any subscriber can afford.The results are inspiring. These innovations enable new mobile communications operators who are delivering 2G, 2.5G, 2.75G and 3G functionality to the most remote and least-serviced regions of the world, connecting their customers to new commercial and financial services, to doctors and emergency medical response, as well as to educational resources — truly changing the world and triggering boundless opportunities.Range Networks also leads the OpenBTS open source project (licensed under AGPLv3), a great tool for experimentation and education on 2G(GSM) and 3G(UMTS) cellular protocols.

OpenBTS (www.openbts.org) is an open source software project dedicated to revolutionizing mobile networks by substituting legacy telco protocols and traditionally complex, proprietary hardware systems with Internet Protocol and a flexible software architecture. This architecture is open to innovation by anybody, allowing the development of new applications and services and dramatically simplifying the setting up and operation of a mobile network.The OpenBTS software is a Linux application that uses a software-defined radio to present a standard 3GPP air interface to user devices, while simultaneously presenting those devices as SIP endpoints to the Internet. - It’s all software, it’s all IP, and it’s open for innovation. - A handset or modem appears as a SIP device, without the need for any special software on the device. - For small networks, the network hardware can be reduced to a single commodity server with a software-defined radio. - Any IP connection can serve as backhaul, including point-to-point WiFi. - All of the software runs on Linux and connects with commonly used IP protocols, so the core network can be virtualized as a cloud service. - Proprietary software found in a conventional cellular network can be replaced with open-source applications. - Because the new network is based on IETF internet-age protocols, developers do not require additional training to deal with archaic legacy technologies.

Development of a new positioning system using existing terrestrial TV signals. Responsible for many critical aspects of system, including: • Design and implementation of multipath mitigation, positioning, and optimal channel selection algorithms. • Embedded software implementation of core signal processing algorithms using ECOS/OpenRISC architecture. Real-time implementation based upon multithreading, interrupts, state machines, etc. • Development of a localized positioning system based upon localized TV transmitters surrounding a building or small area. • Development of messaging protocols for communication b/w user device and positioning server. • Development of hybrid positioning solutions; i.e. combining other signals like GPS, DVB with TV signals.

Development of new signal processing algorithms for improvement of communication system performance, particularly efficient handling of packet retransmissions. Current results include: • A low-complexity diversity algorithm which involves an optimized adaptation of bit-to-symbol mappings per packet retransmission, greatly reducing frame error rates and increasing throughputs in a wide variety of scenarios. • Development of ARQ protocols for MIMO systems, integrating multiple retransmissions via an augmented sphere decoding/detection algorithm. • Optimal linear precoders that enhance the overall channel capacity provided by packet retransmissions in frequency-selective channels. • A low-complexity receiver which reduces frame error rates and increases throughputs by exploiting the inherent diversity of retransmissions through time- varying frequency-selective channels. • A low-complexity channel equalizer based upon iterative decision feedback.

Responsible for algorithm and software design of signal intelligence (COMINT/SIGINT) systems for various government customers. Project involvement includes: • A real-time GSM Environment Analyzer, a product that detects and fully characterizes GSM signals in severe co-channel environments, successfully tested and demonstrated at overseas facilities. • Algorithm development of similar analyzers for EDGE and IS-136 environments. • Development of commercial drive test set software for GSM, IS-136, and EDGE. • Limited development of software for an automatic signal detection and 
classification system involving the use of higher-order cyclostationary statistics. • A novel geolocation algorithm that uses maximum likelihood estimation 
techniques.

Worked in development group of SATCOM product, a digital radio that provides voice and data services for commercial airplanes via the INMARSAT satellite system. Responsible for defining physical layer system requirements and tests for SATCOM products. Project leader for designing a new test apparatus for physical layer testing using advanced signal processing techniques and technologies.

Worked on the RDRN (Rapidly Deployable Radio Network) research project funded by DARPA, contributing to the hardware and signal processing design of a 1.2 GHz, 2 Mbps beamforming digital radio. Also worked on design of a programmable 10 Mbps digital beamforming receiver. Design and implementation of several novel FSK modulation and demodulation schemes, using a TI TMS320C50 DSP. Designed and implemented an “orderwire” radio system, which used 430 MHz amateur packet radios and GPS (Global Positioning System) receivers. Helped created a software radio testbed for DSP demodulation of radio signals.