HetNets, or spatially heterogeneous networks, are wireless communication networks which employ a variety of different kinds of network nodes, separated in scale to service a single communication network. Along with the standard macro-cells, Hetnets allow the deployment of pico/femtocells at the SOHO level, relay-nodes and remote radio heads, etc. The purpose is to maximize system capacity and user perceived quality without requiring additional expensive spectrum.
Early on, HSC recognized that deploying a network of nodes of different scales and abilities requires multiple enabling technologies – Self Optimizing Networks (SON) for continuous adaptation, Inter-Cell Interference Coordination (eICIC) for interference mitigation, carrier-aggregation for instantaneous service of localized high demand, Coordinated Multipoint (COMP) for maximizing network performance in cell-edge situations, and so on. HSC is working with different customers to develop these technologies for deployment in different network nodes.
Small cells (pico/femto cells) are low-power network nodes, designed to be mostly self-sustaining and cover the needs of a few users in a localized coverage area. Instead of having steady state load akin to macrocells, they are expected to have quick bursts of demand, requiring them to be able to co-exist with macro-cells and maximize their performance with the presence of the macro-cell in mind.
HSC is working with customers and partners to architect small cells and relays using off-the-shelf hardware and software platforms. The key challenge is to develop the small cell as a platform – this allows the development of innovative applications (such as our distributed SON application and WiFi loading applications) to improve network controllability and performance.
Take a more in-depth look at our experience with small cell technology here.
eICIC and FeICIC are the terms developed by 3GPP to describe a suite of techniques used to manage interference in cell-edge areas, especially between a femto cell and a macro-cell. Due to the vast difference in power transmission levels between the two, and due to the fact that the macro-cell needs to maintain a certain coverage, 3GPP has defined a large number of active interference management methods on the femto cell’s part, and also some supporting mechanisms (for example Reduced Power Almost Blank Subframes) on the part of the macro-cells.
At HSC we are working with our customers and partners to understand the ramifications of these technologies. One of the crucial areas is the ability of user terminals to receive multiple signals in the face of systematic interference (MAI) and to be able to measure and provide accurate feedback to the networks. We have also worked in this area in the TD-SCDMA field, developing algorithms for extraction of pilots and measurement in an MAI manner. This technology is now being progressed to the LTE Hetnet domain.
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