» Research Areas > LTE 30 May 2020

Home | LTE in General | Fractional Frequency Reuse | Integrated Femto & Macrocell Environments | Forward Error Correction | MBSFN | Our Team | Downloads

AL-FEC integration on ns-3

In order to simulate the application of an AL-FEC protection scheme over 3GPP MBMS environments, we utilize the ns-3 network simulator.

The AL-FEC protection (based on Raptor codes) is modeled on the application source before the transmitted data being forwarded to the core network. More precisely, according to the specified Source Block Length of the FEC block the transmitted packets are organized in AL-FEC source blocks and thereafter the redundant AL-FEC symbols are produced for each source block. The number of the generated additional AL-FEC symbols is determined by the transmission overhead a multicast sender introduces to the transmission. Thereafter, the generated source and repair symbols are transmitted through an IP multicast flow to multiple recipients.

You can download the source code of ns-3 including the AL-FEC integration from here.

Tool for MBSFN area optimization based on spectral efficiency and cost

We have developed a tool (in Lua programming language) which optimizes the MBSFN area configuration based on one of the following two parameters: spectral efficiency and total telecommunication cost.

In the first case the tool estimates the spectral efficiency (SE) of each cell, the resource efficiency (RE) of the network and gradually formulates the optimal network deployment that maximizes the networką s RE. The algorithm starts with an arbitrary distribution of MBSFN cells (for a given interested UE drop area) and then makes random changes to it. For every change it calculates the RE of the system, if it has decreased, it rolls back to the best-known configuration. In many cases though, the changes happen to be beneficial for the RE and thus they are accepted. Gradually, this procedure leads to better configurations. In the case of optimizing the MBSFN area configuration based on the total telecommunication cost, the main idea is to sequentially compare the intermediate calculated costs until we find the minimum total one.

The tool implementing this procedure is available here.

Implementation in Matlab for FFR optimization in OFDMA networks

Our team has developed a Matlab simulation for OFDMA networks. We propose a dynamic FFR mechanism that selects the optimal frequency allocation and inner cell radius based on the cell total throughput and a custom metric which is called user satisfaction (US). In detail, the mechanism divides the cell into two regions (inner and outer). For each potential frequency allocation (FA), the mechanism calculates the per-user throughput, the cell total throughput and US. This procedure is repeated for successive inner cell radius. Afterwards, the mechanism selects the optimal FFR scheme that maximizes the cell total throughput and US.

The source code for the implementation of the above procedure is available here.

A throughput simulation framework for LTE-A systems

One of out latest projects is a MATLAB simulation framework for throughput calculation in every possible point within a LTE Advanced macrocell range. The framework allows user to add buildings in the topology and deploy femto base stations (BSs) in custom spots. Buildings' walls are taken into account for the path loss estimation, derived in case they interfere between the BS and the user equipment (UE), while the rest of BSs cause interference. The user may be attached to the macro or a femto BS. Simulation calculates throughput and other userful information like the SINR and the path loss, for every possible user location.

You can download source code from here.

If you need any help please contact the project team.

• RU6 announces the completion of Intracom Course
• The Western Greece Region and the University of Patras host the fifth study visit of the project
• Launching of project SECOVIA
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