Sharing low-cost wireless infrastructures with telecommunications operators for backhauling 3G services in deprived rural areas

3G small cells are becoming a promising solution for inexpensive 3G coverage in rural small villages, but the high cost of backhaul infrastructures remains an obstacle for the worldwide adoption of this kind of solutions. On the other hand, broadband wireless infrastructures may be found in many rural areas for communications in specific sectors such as health or education services, environmental monitoring, etc. These sectorial broadband communications infrastructures are often multi-hop wireless networks using long-distance WiFi links or WiMAX. We propose the possibility of 3G operators sharing those third parties' infrastructures. It would permit them to have a low-cost backhaul solution for their rural 3G cells in those areas where the expected demand of 3G services does not ensure enough revenues to justify the deployment of dedicated infrastructures. This is a win-win solution because bandwidth-renting may help to achieve financial stability for such sectorial networks, while operators can extend their coverage to regions where this would not be economically sustainable otherwise. This paper studies the technical feasibility of the proposed solution. Different multi-hop broadband rural networks are studied, and a general architecture is derived from them. Then, additional requirements are introduced in order to make such networks support the QoS requirements of 3G voice and data traffic. Three techniques are considered in order to manage the network in such a way that 3G traffic and other traffics may be transported together in the network without compromising the quality of the backhaul: DiffServ, plain MPLS and MPLS-TE. Measurements taken on a real testbed in a laboratory allow us to compare the performance achieved with these three techniques, and the advantages and drawbacks of each of them are presented.