C2POWER

C2POWER main objective is to research, develop and demonstrate energy saving technologies for multi-standard wireless mobile devices, exploiting the combination of cognitive radio and cooperative strategies while still enabling the required performance in terms of data rate and QoS to support active applications.

The promise of a truly mobile experience is to have the freedom to roam around anywhere and not be bound to a single location. However, the energy required to keep mobile devices connected to the network over extended periods of time quickly dissipates. In fact, the operational time, has been identified as the number one criteria by the majority of the consumers purchasing a mobile device. Moreover, concern about exhausting battery lifetime is also one of the main reasons why users do not opt to use advanced multimedia services on their mobiles more frequently.

To avoid the foreseen 4G "energy trap" C2POWER project investigates, develops and demonstrates how cognition and cooperative strategies can be extended to decrease the overall energy consumption of mobile devices while still enabling the required performance in terms of QoS.

C2POWER aim is to contribute to decrease the envisaged rise of power demand in 4G handsets In particular, C2POWER investigates two complementary techniques to increase power efficiency at the wireless interface of handsets:

Cooperative power saving strategies between neighboring nodes using low power short range communications.
Cognitive handover mechanisms to select the Radio Access Technology which has the lowest energy demand in heterogeneous environments.


Sigint acts a work package leader to the work package that investigates and implements energy efficient vertical handovers through the use of a centralized IP-Mobility platform. The scope of this work package is to investigate, develop and demonstrate energy efficient handover policies which to provide the mobile user the best service experience conserving the optimal quality of services (QoS) with power consumption constrains. The Handover decision is based on context-aware vertical handover algorithms which will select the most appropriate interface for a given application/service (voice, video streaming, interactive services etc) among multiple options that would satisfy the requirements and objectives set by the user, always in an energy saving way. These energy-efficient VHO algorithms are developed on top of a mobility platform which will handle the execution of the vertical handover commands. This unit/platform gathers all the information/knowledge regarding the mobile user requirements, capabilities, the network status and network capabilities, process them (cognition) centrally and instruct; if needed, a network initiated vertical handover (VHO). Also, it is under the scope of this work, to research the state of the art in Femtocell technology and exploit the differences between Femtocell and macrocell, as compared to the conventional vertical handover. It also identifies the benefits of short range handover, namely the energy profit a user has when he moves from a Macro to a nearby Femtocell. Both approaches are centrally controlled and are based on contextual information received from both the network and the terminal which improve the handover decisions trying to limit the cases of "false handover".

The C2Power VHO Demonstration architecture shown below was built around Sigint's IP Mobility Platform which is a centrally controlled distributed system and is responsible for provisioning mobility through the execution of Vertical Handovers. It includes the routing functionality to implement a Vertical Handover (VHO) between heterogeneous IP-based Radio Access Technologies (WiFi, UMTS, WiMAX, etc.) and ensure seamless mobility and uninterruptible service provision (data, voice or media). This functionality is implemented on top of an Mobile IP core which ensures that the mobile terminal maintains its TCP/IP address and all its live TCP/IP sessions whenever and wherever is attached to a network, and effectively ensures a transfer of a call/or connection from one RAT to another when needed (vertical handover) in a continuous and seamless way. Apart from the IP-mobility functionality, it includes a central database which houses all the parameters needed for the decision and execution of the VHO. Apart from the integration of the IP mobility platform with the energy efficient vertical handover algorithms Sigint is also involved with the implementation of various context aware modules which provide the necessary information to the central database (also implemented by Sigint) and made available to the algorithms for VHO decision generation. These involve:

Network Discovery modules for Wi-Fi and WiMAX
Power consumption modules for monitoring the live power consumption of the radio adapters on the terminal and also the status of the battery.
A positioning module which is based on GPS and also WiFi indoor positioning Network Emulator which emulates reliable network context (cell load, throughput ect.)


Finally, Sigint develops an energy efficiency module which evaluates at real time the performance of the handovers.