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Project: LTE-Advanced Enhancements using Femtocells

Acronym: NEUF
Main Objective: The project will take LTE-Advanced as a reference and will explore possible enhancements to the support of femtocells. It will use mechanisms to reduce the interference-limited transmission with full frequency reuse. These include CQI, QoS- and interference- aware scheduling and RRM with user-grouping, coordinated RRM, exploiting the spatial degrees of freedoms from multi-antenna systems and OFDMA through MIMO and beam forming techniques, active interference management and CoMP transmission, as well as carrier aggregation for multi-band transmission.
New technologies like aggregate carriers and cooperative multi antennas antenna systems as part of LTE-Advanced systems will be evaluated with respect to their ability to enhance the performance of networked femtocells based on LTE-A. The availability of Positioning information, can help provide the network with information on the terminal positions and, with this, to adapt the transmission scheme to the terminal avoiding worst channel conditions.
At the network layer, considerable research and development has been recently focused on the use of small cellular base stations. However, those cells have only been considered as mere extensions to cellular networks, allowing the enlargement of service coverage. The use of these small cells, mostly deployed by consumers, has not yet been fully explored. There are many services and protocols in the network that could benefit on the scattering of this kind of cell deployment. This project will exploit the opportunities that small cells will bring to improvement on the network architecture. The aim is to a achieve a much richer small cell, that will provide better support for several services and protocols that could take advantage on a distributed architecture and/or context ware and localized information.

Femtocells can have many benefits for both operators and users. From an operational or deployment perspective however their integration into the network is quite hard. From the user perspective the deployment of those cells has to be transparent, therefore support for zero-configuration networking is a requirement. This project will exploit network access characteristics of being self-organized inherent to the SON specification of LTE-A
The project will include specific activities to study mobility management, considering its implication network efficiency. The aim will be to support simultaneous data flows from LTE-A and other access systems (WLAN, WiMAX), provide policies for guiding and configuring the UE IP flow routing via different access systems, enable the dynamic movement of IP flows between access systems (offloading) and support handovers when the UE handles multiple flows. Cross-layer Media Independent Handovers standardization efforts have been done on several working groups in IEEE, IETF and 3GPP. However the implementation of those media independent handovers has not yet fully considered the use of Femtocells in the network. For instance, in IEEE 802.21 access selection is out o scope of the standard, which is simply an integration enabler for multi-access radio access technologies. Femtocells will be used to support handover decisions, by implementing media independent services. Localized information and their use for supporting handovers will be considered in detail. In addition, the project will work on the use of Femtocells on the implementation of decision entities and handover policy management. Simultaneous multi-Access, multi-homing is another novel aspect to consider in femtocells. In particular this project will go beyond “3G complemented by 3rd party access” scenarios, paving the ways for true multi-access, multi-homing where each flow can influence the access selection process.
The project will take advantage of Femtocells in multiple ways. The project will exploit the fine-grained context awareness made possible by the use of Femtocells in order to support the provision of content rich services by increasing the user’s Quality of Experience (QoE).
Reference: PTDC/EEA-TEL/120666/2010
Funding: FCT/PTDC
Start Date: 01-03-2012
End Date: 01-03-2014
Team: Rui Miguel Neto Marinheiro, Américo Manuel Carapeto Correia, Rui Miguel Henriques Dias Morgado Dinis, Nuno Manuel Branco Souto, Pedro Joaquim Amaro Sebastiao, Fernando Jose da Silva Velez, Mário Pedro Guerreiro Marques da Silva, João Carlos Marques Silva, Rui Filipe Rosa Paulo, José André Rocha Sá e Moura
Groups: Radio Systems – Lx, Radio Systems – Av
Partners: UNINOVA
Local Coordinator: Rui Miguel Neto Marinheiro
Links: Internal Page
Associated Publications