24 research outputs found
Phantom Cell Architecture for LTE and its Application in Vehicular IoT Environments
Proliferation of Internet of Things (IoT) devices (smart wearables/vehicles, etc.) in the near future, would raise the capacity and bandwidth demands from the cellular infrastructure manifold. Deploying small cells is an effective solution to cope with the problem. This work focuses on a special kind of small eNBs, termed as Phantom eNBs. Phantom eNB acts as a supplement to the current radio access network (RAN) in the LTE infrastructure. It handles the data plane while a Macro eNB holds the control plane. Definitions of control and data plane, along with the modifications needed in the protocol stack are explained i n this paper. Communication mechanisms are developed for Phantom and Macro eNB to communicate over the X2 interface between them. NS-3 simulations are performed for handover scenarios of Vehicular IoT environment, consolidating the architecture and network topology designed for Phantom based Heterogeneous Networks (HetNets). Network throughput improvements of 80% and 14% are observed in comparison to the Macro-only RAN and existing small cell solutions (Femto cells), respectively
A Socio-inspired CALM Approach to Channel Assignment Performance Prediction and WMN Capacity Estimation
A significant amount of research literature is dedicated to interference
mitigation in Wireless Mesh Networks (WMNs), with a special emphasis on
designing channel allocation (CA) schemes which alleviate the impact of
interference on WMN performance. But having countless CA schemes at one's
disposal makes the task of choosing a suitable CA for a given WMN extremely
tedious and time consuming. In this work, we propose a new interference
estimation and CA performance prediction algorithm called CALM, which is
inspired by social theory. We borrow the sociological idea of a "sui generis"
social reality, and apply it to WMNs with significant success. To achieve this,
we devise a novel Sociological Idea Borrowing Mechanism that facilitates easy
operationalization of sociological concepts in other domains. Further, we
formulate a heuristic Mixed Integer Programming (MIP) model called NETCAP which
makes use of link quality estimates generated by CALM to offer a reliable
framework for network capacity prediction. We demonstrate the efficacy of CALM
by evaluating its theoretical estimates against experimental data obtained
through exhaustive simulations on ns-3 802.11g environment, for a comprehensive
CA test-set of forty CA schemes. We compare CALM with three existing
interference estimation metrics, and demonstrate that it is consistently more
reliable. CALM boasts of accuracy of over 90% in performance testing, and in
stress testing too it achieves an accuracy of 88%, while the accuracy of other
metrics drops to under 75%. It reduces errors in CA performance prediction by
as much as 75% when compared to other metrics. Finally, we validate the
expected network capacity estimates generated by NETCAP, and show that they are
quite accurate, deviating by as low as 6.4% on an average when compared to
experimentally recorded results in performance testing
Statistical Relationship between Interference Estimates and Network Capacity
Interference is a major impediment to the performance of a wireless network as it has a significant adverse impact on Network Capacity. There has been a gradual and consistent densification of WiFi networks due to Overlapping Basic Service Set (OBSS) deployments. With the upcoming 802.11ax standards, dense and ultra-dense deployments will become the norm and the detrimental impact of Interference on Capacity will only exacerbate. However, the precise nature of the association between Interference and Network Capacity remains to be investigated, a gap we bridge in this work. We employ linear and polynomial regression to find answers to several unexplored questions concerning the Capacity Interference Relationship (CIR). We devise an algorithm to select regression models that best explain this relationship by considering a variety of factors including outlier threshold. We ascertain the statistical significance of their association, and also determine the explainability of variation in Network Capacity when Interference is varied, and vice versa. While the relationship is generally believed to be non-linear, we demonstrate that scenarios exist where a strong linear correlation exists between the two. We also investigate the impact of WMN topology on this relationship by considering four carefully designed Wireless Mesh Network (WMN) topologies in the experiments. To quantify endemic Interference, we consider four popular Theoretical Interference Estimation Metrics (TIEMs) viz., TID, CDALcost, CXLSwt, and CALM. To ensure a sound regression analysis, we consider a large set of 100 Channel Assignment (CA) schemes, a majority of which are generated through a Generic Interference aware CA Generator proposed in this work. Finally, we test the TIEMs in terms of their reliability and the ability to model Interference. We carry out the experiments on IEEE 802.11g/n WMNs simulated in ns-3