|DEVOTI FRANCESCO||Cycle: XXXII |
Tutor: CESANA MATTEO Major Research topic
:Context Based Resource Management in 5G Wireless Access Networks
Advisor: CAPONE ANTONIOAbstract:
In the future 5G wireless access networks guaranteeing high peak rates and low latency is no longer an option, this is pushing mobile operators to deploy Heterogeneous Networks to inject capacity in the wireless access network with a pretty large number of small cells (size up to a 100-200 meters) installed in the area of macro cells.
Small cells will use frequencies above the conventional 5GHz. A promising opportunity is represented by millimeter wave (mm-wave) communications, which give additional unlicensed spectrum band and provides extremely wide bandwidths (up to 1GHz), enabling ultra high data rates.
The introduction of mm-wave technologies in cellular networks is not straightforward due to harsh mm-wave propagation conditions that limit the mm-wave access availability. mm-wave technologies require high-gain antenna systems to compensate for high path loss and limited power. As a consequence, directional transmissions must be used, thus increasing the system complexity.
In order to integrate mm-wave technologies with conventional wireless networks, new 5G network architectures are currently being investigated. In these architectures a functional split between C-plane and U-plane allows to guarantee the availability of a signaling channel through conventional wireless technologies, with the opportunity to convey context information from users to network, and transfer data using mm-wave bands.
The separation in these new network architectures allows mobile terminal to access the service contacting the control plane of a base station and being assigned radio resources for data transmission on a different base station. Network resource management should exploit the privileged centralized position of the control plane to provide innovative solutions in order to select the most suitable resources in an adaptive and much more efficient way than classic distributed protocols.
Context information (such as user profiles, user positions, quality requirements, network status, etc.) becomes a crucial aspect for exploiting the flexibility of the new architecture with a role much more relevant than in traditional networks for system performance and efficiency.
The objective of my research is to propose an efficient small cell selection and resource allocation in 5G wireless access networks based on: i)current context information ii)previous system history iii)context prediction.
Context information will be used to provide to the C-plane an overview on the current network status that allows the network to arrange dynamically and in an optimal way the resource allocation, for example the C-plan can take the decision to activate or not some small cell based on the user positions and user density distribution, or choose which small cell is suitable for the user based on the current network load and the user position. Here is crucial to investigate on how the context information type and quality can lead to an effective resource allocation.
Previous system history can be used to take trace on which decisions taken by the network were effective in some context conditions, in order to make the access network adapted to the area in which it is deployed. This is important since the transmissions will be directional and the area topology where small cells are deployed can affect seriously the network performance.Context prediction can be used by the C-plane to make a prediction on the future network status, allowing the network to allocate resources in an anticipatory way, and so, be more reactive to context changes. As examples, by traffic estimator and predictor is possible to pre allocate resources for the new user, or, by tracking the user position, switch on the possible future micro cell. Here is important to limit the waste of resource due to possible wrong prediction.
The main work will be the developing of algorithms that exploits the overall vision available from the new network architecture and able to deal with the mm-wave environment. The related activities will be supported by the development of experimental testbed to test the proposed solution, by exploiting simulation tools. This will allow the evaluation of potential benefits and issues related to the implementation of such algorithms in real mm-wave access networks.