Wiback

WiBACK
Introducing Fraunhofer’s Wireless Backhaul Technology

An overview about the concepts and the current status (as of July 2011) of our ongoing research & development efforts

Purpose of this Document
This document introduces Fraunhofer’s WiBACK – Wireless Backhaul Technology.

MOTIVATING WIBACK
Most rural areas throughout the world experience bad connectivity to the Internet.Companies suffer from inferior competitiveness and the populations from digital exclusion. One of the reasons is the lack of technology to enable an appropriate business case for high-bandwidth service-provisioning in many deployment scenarios. WiBACK is the result of several years of research and development at Fraunhofer FOKUS. It was motivated by the intention to provide carrier-grade servicequalities for voice and data transmission over a large area with low-cost wireless technology. From a technological point of view, the WiBACK core can be positioned between point-to-point radio links and fibre-optic backbone networks. In its deployment, WiBACK is supplemented by access technologies such as Wi-Fi, GSM, and UMTS.

WIBACK DEPLOYMENT SCENARIOS
The typical scenario for WiBACK is asfollows: One or multiple edge nodes connecting to a fixed and reliable network infrastructure are available. These can be provided by a commercial service provider or they can be interfaces to the existing network of an operator. Located far from these edge nodes, multiple locations require high-quality connections to a voice or data network / the Internet. What “far” means depends on the localsituation. In particular, the challenge cannot be easily solved by a simple point-to-point radio-link or by digging cables into the ground. WiBACK provides the technology to connect infrastructure edge nodes to (many) user access points.

Figure 1: Wireless Mesh Deployment Scenario

Examples for this deployment include temporary wireless networks for large events, fast network deployment in disasterareas, broadband Internet services for rural areas, and wireless wide-area infrastructures in emerging regions. Key features that make Fraunhofer’s WiBACK unique are the combination of      a wireless network that can span huge distances (several hundred km); provisioning of carrier-grade (guaranteed) service qualities for voice and data traffic; low capital expenditure (CAPEX) due to theuse of commercial off-the-shelf hardware (typically IEEE 802.11 mass-market components); low operational cost (OPEX) due to auto-configuration and self-management capabilities, as well as low energy consumption; the possibility to run most nodes in the network on solar energy due to their energy efficient hardware and software, and the integrated solar charger.

WiBACK is not an alternative to amobile operator network. It provides a transport infrastructure and complements existing technology, rather than replacing it. While WiBACK supports different types of access technologies (including GSM) at the user frontend, it expects an IP-based network at the back-end. Typical mobile-operator services such as roaming or hand-over need to be implemented on-top of WiBACK.

A CLOSER LOOK ATWIBACK HARDWARE
Taking a closer look at the hardware, different types of components can be identified: The Wi BACK Gatewa y is located at the interface between a WiBACK wireless mesh and a fixed network infrastructure. Most of the network logic is implemented in this node, including monitoring and network management functions. Conceptually multiple Gateways can be connected to a network, in order toreduce the risk associated with a single point of failure. The Gateway manages traffic paths inside the WiBACK mesh, and ensures that links with an associated service quality will never be overloaded. In particular, links for voice traffic will always run at very low latency and close-to-zero packet loss. The WiBACK repea ter is a wireless node with two radio interfaces. It is typically located...