All-wireless Network of Femtocells
The all-wireless network of femtocells (NoF) testbed is an example of hybrid wireless networks in that it integrates the 3GPP architecture and wireless data networking concepts. This deployment scheme allows femtocells to be deployed even if no data cables are available, as only those nodes acting as gateways (i.e., Local network of Femtocells GateWay, LFGW) are connected through a wired data link towards the core network. Therefore, at the transport level, the Iuh interface between the femtocells and the UMTS network emulator first traverses a multi-hop wireless network up to the LFGW, and then, the wired network up to the emulator. In the multi-hop wireless network, we have deployed a distributed geographic+backpressure routing, which also allows local communication between user equipment (e.g., mobile phones) in the NoF without reaching the core by means of Local IP Access (LIPA).
The main characteristics of each of the components of this testbed are:
- Mesh Testbed
- Multi-radio WLAN wireless mesh network
- 12 wireless mesh routers deployed in the first floor of the CTTC building
- Cellular Testbed
- Real HSDPA Node B
- Emulated RNC + UMTS core network (incl. GGSN towards the Internet)
- 20 HSDPA/UMTS cards
- 12 Sagemcom femtocells deployed next to each of the above multi-radio WLAN nodes
- Iuh interface with core network emulator
- EXTREME Testbed
- It is integrated in the general framework for experiment configuration and management
Up to now, the testbed has been mainly used for evaluating routing and load balancing in the local all-wireless network of femtocells. We implemented our distributed geographic+backpressure routing that reuses ns-3 code by means of the ns-3 emulation framework.
In the first video, there is a brief explanation of the testbed. The initial part of the second video also explains a bit the setup as well as the general experimentation framework. The second video mainly focuses on the implementation issues of our distributed geographic+backpressure routing and some preliminary evaluation carried out over the testbed using the ns-3 emulation framework.
Brief description of the NoF testbed
Implementation issues and performance evaluation
For a list of publications on distributed geographic+backpressure routing, including those discussing the implementation issues and performance evaluation, please visit this page.
This testbed was developed during the course of various projects, most notably EU project BeFEMTO and MICINN project SYMBIOSIS.