An efficient SDN‐based LTE‐WiFi spectrum aggregation system for heterogeneous 5G networks

• Published in: Transactions on emerging telecommunications technologies Vol. 33; no. 4
• Main Authors: Abbas, Khizar, Afaq, Muhammad, Ahmed Khan, Talha, Rafiq, Adeel, Iqbal, Javed, Ul Islam, Ihtesham, Song, Wang‐Cheol
• Format: Journal Article
• Language: English
• Published: 01.04.2022
• DOI: 10.1002/ett.3943
• ISSN: 2161-3915

Summary Nowadays, the continuously increasing demand for high data traffic and providing different quality of services (QoS) to the customer are very challenging tasks for all network operators. In the last few years, mobile data traffic is increased to a significant extent and half of the traffic is provided through WiFi technology which is known as WiFi offloading. To overcome the increasing traffic demand, WiFi offloading is the best option to reduce the burden of cellular networks. So, by aggregating existing indoor WiFi technology to the cellular network increases the network capacity and provides better QoS to customers. In this article, we propose and implement the LTE‐WiFi aggregation system where eNodeB is responsible for the aggregation of the WiFi access point without modifying the core network. Furthermore, the proposed system is integrated with the mobile‐CORD (M‐CORD) platform which leverages software defined networking (SDN), network function virtualization (NFV), and cloud technologies for providing a 5G environment. M‐CORD platform has three main modules: service orchestrator (XOS), SDN controller ONOS, and OpenStack. One of the important features of M‐CORD is to provide virtualized core network functions that enable the users to automatically customize, monitor, and control the resources of the network. Due to ONOS controller support, we can easily scale up the network instances by giving the configurations to service orchestrator XOS of the M‐CORD. The implementation of the proposed system is based on the OpenAirInterface (OAI) platform which provides open sources implementation of core and access networks. The aggregation of both LTE and WiFi technologies is done at the PDCP layer in a very tight coupling way. Moreover, we test our proposed system with three kinds of policies for UDP and TCP traffic: LTE only, WiFi only, and LTE‐WiFi aggregated. The experimental results show that our proposed LTE‐WiFi aggregated system gives better performance and provides high bandwidth as compared to the LTE network. The Figure presents the proposed system architecture, which is deployed in two phases: the first phase consists of the deployment of the LWA system in a very tight coupling fashion in which WiFi AP is directly connected to eNodeB and eNodeB is responsible for handling WiFi traffic. For that aggregation OAI (OpenAirInterface), 5G RAN is deployed with software‐defined radio (SDR) USRP B210. After that RAN part is aggregated with WLAN AP, both technologies are aggregated at the common PDCP layer. The UE can communicate with both technologies, that is, LTE and WiFi simultaneously. The second part of this system is to integrate the LWA system with the M‐CORD platform for better monitoring and control. The M‐CORD platform is the best option because it supports OAI LTE network functions (NFs) and provides an open‐source 5G environment for testing. So, the M‐CORD system controls the LWA system with XOS which automatically deploys the services to the mobile network. XOS treats everything like a service and each service has synchronizer which acts as a communicator between different services. Afterward, the vEPC of the M‐CORD which is controlled by the XOS is connected to LTE‐WiFi aggregated system. So, the LWA system is totally outside the M‐CORD and XOS should be able to monitor and control it with the help of synchronizers.