Wireless Networks

Brief Introduction

Wireless networks are inherently more subject to change than wired ones. Given mobility and interference, as well as energy/power constraints, many wired "cooperative" protocols (e.g. for packet routing/forwarding) are simply not readily adoptable for the wireless medium. With so much competition for resources in the overcrowded unlicensed and cellular-licensed bands, cooperation, an essential feature of networking, has to be incentivized. Using cooperative and non-cooperative game theory, we tackle this problem in an array of wireless scenarios, with a focus on forth-generation (4G, LTE) and fifth-generation (5G) technologies.


Current Projects:

1. Cloud Radio Access Network (C-RAN)

Cloud Radio Access Network (C-RAN) is a novel mobile network architecture which can address a number of challenges the operators face while trying to support growing end-user’s needs. The main idea behind C-RAN is to pool the Baseband Units (BBUs) from multiple base stations into centralized BBU Pool for statistical multiplexing gain while shifting the burden to the high-speed wireline transmission of In-phase and Quadrature (IQ) data. C-RAN enables energy efficient network operation and possible cost savings on baseband resources. Furthermore, it improves network capacity by performing load balancing and cooperative processing of signals originating from several base stations.

I- Towards CRAN implementation: It is possible today to run LTE RAN functions of software implementation over General Purpose Processors (GPPs) on Intel/ARM, rather than the traditional implementation over Application-Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), or Field-Programmable Gate Arrays (FPGAs). Different software implementations of the LTE base station, which is referred to as evolved Node (eNB), already exist:

  1. OpenAirInterface (OAI) developed by EURECOM, which is an open-source Software Defined Radio (SDR) implementation of both the LTE RAN and the Evolved Packet Core (EPC).
  2. Amarisoft LTE solution, which is a pure-software featuring a fully-functional LTE eNB,
  3. Intel solutions featuring energy efficiency and high computing performance using a hybrid GPP-accelerator architecture and load-balance algorithms among a flexible IT platform.

Using OAI open source architecture we aim to implement a software based LTE on Linux machines.

II- Resource Allocation in CRAN especially among D2D enabled users: Collaboration among pooled BBUs paves the way for innovative ideas on system performance improvement within the next generation of the cellular networks. Recently born techniques such as Coordinated Multipoint Point (CoMP) showcase the potential benefits of cooperation among BBUs. On the other hand, using off-loading methods, such as underlying/overlaid Device-to-Device (D2D) communication and WiFi-direct, is inevitable to address future bandwidth devouring applications. We aim to dig into the resource allocation problem among D2D and/or WiFi-direct enabled users in cellular networks with CRAN architecture.

Finished projects:

1. Energy-Aware Optimization and Mechanism Design for Cellular D2D Networks

In a device-to-device (D2D) local area network (LAN), mobile users must cooperate to download common real-time content from a wireless cellular network. However, sustaining such D2D LANs over cellular networks requires the introduction of mechanisms that will incentivize the MUs to cooperate. In this work, we study the problem of energy-aware D2D LAN formation over cellular networks. we formulate this problem using a game-theoretic framework in which each MU seeks to minimize its energy consumption while actively participating in the D2D LAN. To account for the selfish behavior of the MUs, a punishment and incentive protocol is proposed in order to ensure cooperation among MUs.

2. Non-cooperative Behaviors between Things in IoT Networks

Internet-connected devices have existed for decades, while recently these devices have permeated into our lives and are popularly conceptualized as the Internet of Things (IoT). IoT is composed of physical objects equipped with “mostly” constrained hardware providing some computing and networking support. IOT networks are large-scale networks consisting of several heterogeneous things and some gateways. The things are sensing different data from the environment and send their measurement data towards the gateways possibly via multiple hops. Since the things are often battery powered, an important design criterion for IOT networks is the maximization of their lifetime.

In this research, we consider different IOT applications, by which we mean a set of things that co-exist at the same physical location, but run by different applications by different security level. We study this problem in a game theoretic setting, and show that, in most cases, there is a Nash equilibrium in the system, in which at least one of the strategies is cooperative, even without introducing any external incentives (e.g., payments).