The evolution of mobile networks from the first to fourth generation has made smart devices and technologies a significant part of our daily activities. The 5G network is a ground-breaking technology that proposes to transform the way individuals use the internet, via the creation of enabling atmosphere. 5G promises faster and superior quality with better security guarantee in comparison to preceding technologies. The software defined networking (SDN) on the other hand is an enabling technology needed to actualize the huge promises of 5G network. This article will analyze the use of Software Defined Network (SDN) in a 5G (fifth generation) network that can be faster and reliable.
Researches are currently exploring different architectures to imply main concepts of this new technology. SDN has been proposed as a promising technique for these networks, which will be a key component in the design of 5G networks. The 5G is going to be based on user-centric concept instead of operator-centric as in 3G or service-centric as seen for 4G.
This new generation 5G of wireless broadband network will provide the
fundamental infrastructure for billions of new devices with less predictable
traffic patterns will join the network. To be succeed with this new technology, going through intelligence is really crucial, to proceed to successful deployment and realization of a powerful wireless world.
Principals of virtual network management and operation, which can be
implemented by network function virtualization (NFV), and Software-Defined Networking (SDN) are the main element of the network architecture to support the new requirements of the new powerful wireless communication in the future.
Software Defined Network (SDN)
Software-Defined Network (SDN) has emerged as a new intelligent architecture for network architecture to reduce hardware limitations. A software-defined network is a communication device under the networking section that controls the functionality of the networking devices and makes a separation of data. The main idea of introducing SDN is to separate the control plane outside the switches and enable external control of data through a logical software component called controller. SDN provides simple abstractions to describe the components, the functions they provide, and the protocols to manage the forwarding plane along with Mobile IP from a remote controller via a secure channel. In conclusion, the inability of mutual access between different parts of heterogeneous networks would be solved. This abstraction is used instead of the common requirements of forwarding tables for a majority of switches and their flow tables. Hence, the controller monitors network packets, publishes policy, or solves errors according to the monitoring results.
A number of northbound interfaces (connection between the control plane
and applications) that provide higher level abstractions to program various
network-level services and applications at the control plane. The OpenFlow
standard has been exploited as the dominant technology for the southbound
interface (connection between the control plane and network devices). This
scheme allows on-demand resource allocation, self-service provisioning, completely virtualized networking, and secures cloud services. Thus, the static network would be evolved into a truly flexible service delivery platform that can respond rapidly to the network changes such as: end-user and market needs, which greatly simplifies the network design and operation. Moreover, the devices themselves no longer need to understand and process thousands of protocol standards but they should be capable of understanding instructions from the SDN controllers.
The networking devices that are controlled by a software Defined network include packet switches, routers, and local area network (LAN) switches. The devices must have well-defined application programming interface (API) between two connected devises.
The devices used under networking in big organizations are routers, networks, and other networking devices that encompass the control functions and data making it difficult to alter the network infrastructure within a system.
Fig 1. Overview of SDN Architectural plane with the SDN Controller
Fig 2. The SDN architecture
Facing the rapidly growing needs of users, Internet service providers cannot afford huge upgrades, adaption, or building costs, as hardware elements are expensive. Therefore, another advantage of exploiting SDN is to make it easier to introduce and deploy new applications and services than the classical hardware-dependent standards.
The ultimate goal of SDN is to create a network that does not need any the design or adjustments of the administrator interference, so, the network can be implemented fully automated administration. The administrators can manage the network through the controller plane more easily with dictating the required policy to the routers and switches, while they have a fully function monitoring over the network.
Software defined networking (SDN) is bringing about a paradigm shift in networking through the ideas of programmable network infrastructure and decoupling of network control and data planes. It promises simplified network management and easier introduction of new services or changes into the network. Use of SDN concepts in 4G/5G mobile cellular networks is also being seen to be beneficial (e.g., for more effective radio resource allocation through centralization, seamless mobility across diverse technologies through a common control plane)
Research and development activities on 5G technologies have attracted lots of interest in both academia and industry worldwide over the last several years. The 5G technology is being seen as user-centric concept instead of operator-centric as in 3G and service-centric as seen for 4G. In 5G, mobile terminals will be able to combine multiple incoming flows from different technologies. It aims to provide single user terminal that can cooperate in different wireless networks and overcome the design problem of power-consumption and cost old mobile terminals. The new 5G technology should be enable the development and exploitation of massive capacity as well as connectivity of complex and powerful heterogenous network. The new infrastructure should be able to handle the complex context of operations to support diverse set of new as well as yet unforeseen services, users and applications. It should be able to flexible and scalable for wildly different network deployment scenarios, in an energy efficient and secure manner.
5G networks will not be based on routing and switching technologies anymore, instead it will be more open and flexible, and will be able to evolve more easily than the traditional networks. They will be able to provide convergent network communication across multi-technologies networks such as packet or optical networks and provide open communication system to cooperate with satellite systems, cellular networks, clouds, data-centers, home gateways, and many more open networks and devices. 5G systems will be autonomous and sufficiently able to adapt their behavior depending in the user’s requirements to handle application-driven networks in dynamic and versatile environments.
Fig 3. The 5G architecture
Moreover, the 5G network will be able of handling user-mobility to guarantee the connectivity at any situation. The end users’ terminals make the final choice among different access networks for the best connection. Also, the terminals will also stay awake and looking for to choose the best technology to connect, with respect to the dynamic changes at the current access technology. The infrastructure of the wireless networks will be based on SDN, which provides arrange the communication between the applications and services in the cloud and user’s mobile terminal. Therefore, the network can be managed on the real-time needs and status dynamically, and it will have benefit from resource virtualization. The architecture of 5G network based on SDN scheme has shown in Fig 4.
Fig 4. SDN-Based oriented network architecture
Implementation of SDN for 5G network
In this section, we are going to introduce some of the most important and familiar methods and architecture which has been employed for implementation of SDN for 5G network.
One of the most popular architecture for leveraging SDN for 5G wireless network is Soft-Air. At the proposed architecture, control plane managed by network servers, provides the management and optimization tools for data plane, which is managed by cellular core network, consists of software-defined base stations (SDBSs) in the RAN and software-defined switches (SD-switches). The controller serves physical, MAC, and network functions on computers and remote data centers. The overall architecture and controller/data plane scheme of the system have been shown in Fig 5 and Fig 6, respectively.