Leveraging advances inmobile broadbandtechnology to improve environmental sustainability

FREE-DOWNLOADH Claussen, LTW HoTelecommunications Journal

Advances inmobile access broadbandtechnology have a high potential to improve environmental sustain- ability both directly by enabling novel network deployment concepts and indirectly by changing the way people live and work. In this paper, improvements of the network

Introduction to Broadband Wireless Access The focus of meeting the growing need for broadband access has shifted onto cover rural and remote areas with relatively lower user density and no network infrastructure [Bernardi10]. Broadband Wireless Access (BWA) is now considered a promising alternative due to the availability of low cost commodity wireless hardware, newly freed spectrum and the progress in communication technology.

Wireless Optical Broadband Access Networks (WOBAN) is a popular BWA architecture. It has a wired optical backhaul network at back end and a wireless mesh network at front end. The wireless part provides access to end users and the wired part carries the aggregated traffic from the wireless part. Such an architecture is shown in Figure 1. The optical backhaul network consists of a Passive Optical Network (PON), an Optical Line Terminal (OLT) in the Central Office (CO) that is connected to multiple Optical Network Units (ONUs) via optical fiber. At the front end, end users access the network through the wireless mesh that has stationary gateways. The user traffic travels over multi-hop through the gateway and reaches ONUs. WOBAN's popularity lies in that it can achieve cost-effectiveness due to the wireless access while having high capacity because of the optical backhaul.

There are multiple research efforts aimed at improving WOBAN such as management system and energy efficiency. Therefore the WOBAN architecture serves as a base for later discussion from the above aspects. Other researchers refer to WOBAN as FiWi BAN (Fiber Wireless Broadband Access Networks). To maintain the consistency between this survey and the references, we use the same terminology as the source. Therefore the term FiWi BAN may appear when discussing relevant works.

General BWA networks design involves several topics. The fundamental one, firstly, is to improve the capacity of the access network. Various works have been proposed including optimal relay station placement, bandwidth allocation scheme and direct communication mode between subscriber stations. Other relevant works focus on management systems for large-scale BWA networks and the performance comparison of multiplex techniques for 4G.

Another crucial concern when considering deploying BWA networks is energy and cost efficiency. Reducing the energy consumption not only saves electric billing but also helps to reduce carbon dioxide emission and is environment-friendly. Lots of research efforts have been put into this issue such as the study of energy efficiency from an architectural level, a mixed capacity access proposal, the study for reducing energy in long reach access and a green WOBAN design. Other important topics on BWA include the enhancement to survivability and specific application scenarios that can benefit from BWA networks. add