Routing Optimization | COMPARING INNOVATION ROUTING AND 4G REQUIREMENTS

At the early days of the Internet, routing took into account the number of hops an as important metric for path selection. This was a wise decision at the time as most of the Internet was still homogenous in terms of its links, router capacity and traffic. Soon later, weights were associated to links giving autonomous systems a new criterion to decide on the best routes and a mean to engineer their traffic and balance this. The creation of labels by MPLS provided a similar traffic engineering mechanism capable of controlling and improving the routing and service delivery through path selection.

In the new context of 4G networks, routers must deal with different dynamic link stability levels, security and QoS levels and network handoff It is for such reasons that the 4G networks will certainly need to also consider new routing metrics and change these according to their environment or context. Under some scenarios, reachability could be more important than performance whereas QoS may become the metric of choice in other circumstances. This may also be service and application driven. Electronic mail transfer is a store and forward application that requires information integrity mainly whereas video conferencing considers low delay and bandwidth as primordial network resources.

Future 4G will certainly embrace disruptive connections and delay tolerant networks, high mobility users resulting in a challenging mix with different routing metaphors and techniques thriving within a single 4G unifying architectures. A simple, "one hat fits all" approach to routing cannot be the way forward. Therefore 4G needs to consider multi-metric optimization following different innovative routing approaches instead of merely reusing traditional strategies. It is believed that new routing and resource management insights borrowed from areas as diverse as biology, social phenomena, random and probabilistic diffusion models are expected to lead the way ahead.

But this is nonetheless not a complete breakaway from routing as we know it. In fact one expects to continue making use of useful traditional concepts such as clustering and hierarchical structures to simplify, organize and improve 4G routing. Following a dynamic approach, social algorithms exchange messages to find popular nodes and establish similarity among them in order to create clusters and hierarchical structures. Similarly to traditional routing algorithms from fixed networks, messages can be forwarded from any social node to a popular one judged to be in a better position to disseminate the information and capable of increasing the probability of a message reaching its destination. This offers ways to increase the delivery rate, but differently from the flooding algorithm, the social strategy reduce s the number of message replication as these messages only are forwarding among a restricted number of nodes. Moreover, approaches such as SOLAR and (Leguay, Friedman & Conan, 2006) work by extracting location information to identify mobility patterns in order to improve their routing efficiency. They rely therefore on the understanding of user's behaviors in terms of mobility patterns 4G networks are expected to collaborate with each other independently of their underlying technologies. For example, a user with Bluetooth and GPRS devices can choose one or another technology to disseminate a given type of information according to application level criteria such as urgency and destination distance. One could use an epidemic algorithm to send a simple message to a friend through a Bluetooth interface while selecting a GPRS interface to transfer credit (possible future money) to a distant family member.