Zeeshan Kaleem

QoS priority-based dynamic frequency band allocation algorithm for load balancing and interference avoidance in 3GPP LTE HetNet

A 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system uses the concept of two-tier heterogeneous networks (HetNets), where low-power and short-range femtocells are laid under macrocells to fulfill the quality of service (QoS) requirements of users and to boost overall network capacity. However, co-channel interference is one of the major issues that need to be resolved for the successful deployment of HetNets. To overcome this problem, fractional frequency reuse (FFR) schemes have been proposed that can efficiently utilize the available spectrum. Nevertheless, these schemes waste limited frequency resources owing to their static allocation and lack of following QoS requirements, network loading conditions, and service priority of users. In this paper, a QoS-based dynamic FFR (QoS-DFFR) scheme is proposed that efficiently allocates the non-occupied center-zone frequency bands, i.e., bonus bandwidth (BBW), to cell-edge users by considering their QoS requirements. Consequently, the proposed QoS-DFFR scheme can optimize cell-edge user throughput and sector throughput and reduce co-channel interference by dynamically allocating the BBW to the most demanding cell-edge users. The proposed QoS-DFFR scheme improves performance because of its ability to dynamically allocate the limited portion of the frequency bands based on the service priorities of users. The system-level simulation results show that the proposed QoS-DFFR scheme performs remarkably well in a HetNet environment. Compared with the usual FFR schemes, the proposed scheme almost doubles the cell-edge users throughput and reduces the users packet loss rate.

Smart and Energy Efficient LED Street Light Control System Using ZigBee Network

The world is converging towards wireless as a communication channel and at the same time facing energy and environmental problems. The solution is by mingling the information technology (IT) and power. Streetlights are among a citys most important and expensive assets usually costs one third of the electricity bill. The proposed smart light control system outclasses the previous systems because it integrates the low power communication protocol Zig Bee with the LED lights. The system reduces the power of the LED lights according to outside conditions of light intensity as it has the ability to dim the lights. The initial experimental results show that it saves remarkable power as compared to conventional systems. This efficiency increases even two fold by considering the advantage of remotely monitoring and controlling the lights through the centralized point. Thus the proposed system is the cost effective and efficient system satisfying the needs of the modern users.

Public safety users’ priority-based energy and time-efficient device discovery scheme with contention resolution for ProSe in third generation partnership project long-term evolution-advanced systems

A device-to-device (D2D) discovery scheme is key enabler for proximity-based services in third generation partnership project long-term evolution-advanced systems for public safety (PS) and general LTE scenarios. The deployment of D2D networks results in severe co-channel interference between conventional cellular users and D2D users, and faces proximity interference management challenges because of the co-existence of multiple D2D users. We propose a time and energy-efficient contention-resolving device discovery resource allocation (TEECR-DDRA) scheme that has the capability to enhance the success ratio for discovery of D2D users by reducing collisions among users. Moreover, the proposed TEECR-DDRA scheme has the ability to prioritise PS users to meet their QoS and latency requirements. Furthermore, multi-channel slotted ALOHA with energy sensing can be used to increase the probability of successful discovery of non-PS users. This ability helps to reduce the discovery time of PS users under disaster scenarios, and also reduces the energy consumption of non-PS users by minimising the number of beacon retransmissions. System-level simulations show that the proposed TEECR-DDRA scheme performs remarkably well under D2D network. Compared with the conventional random access scheme, the proposed scheme almost doubles the discovery range and significantly improves the success ratio for discovery of D2D users.

Public Safety Priority-Based User Association for Load Balancing and Interference Reduction in PS-LTE Systems

This paper addresses the issues of user association in multi-tier heterogeneous networks (HetNets) to reduce co-channel interference and provide load balancing for proactively offloading users onto mobile personal cells (mPC). Previously, much of the literature discussed the user’ association problem for HetNets with conventional fixed small cells. The problem discussed in the existing literature is easy to analyze owing to fix nature of the small cells. In this paper, we focus on the mPC instead of fixed small cells, which complicates the user association problem due to its nature of mobility. In this paper, we propose the public safety (PS) users priority-based mPC user association (PS-UA) scheme for load balancing and interference reduction in highly fluctuating PS long-term evolution systems. The proposed scheme improves the user-association problem by minimizing call blocking probability (CBP) according to the network load conditions and PS user priority. Moreover, it further improves user signal-to-interference-and-noise ratio by implementing enhanced intercell interference coordination scheme to further reduce the interference to the offloaded users. System-level simulations confirmed the validity of the proposed PS-UA scheme, because it convincingly reduces the CBP for PS users as compared with the conventional static user association scheme.

Uplink power control for interference mitigation based on users priority in two-tier femtocell network

In recent years, femtocells are receiving considerable attention towards increasing the network coverage, capacity, and improving the quality of service for users. However, as the femtocells use the same radio band, it poses a serious cross-tier interference issue. In this paper, a reasonable and effective interference suppression scheme, that is, quality of service based fractional power control (QoS-FPC) under the HetNet environment is proposed. The proposed scheme limits the cross-tier interference at eNB below a given threshold, and hence results in the optimization of femtocell users power allocation and system throughput.

Neighbors’ interference situation-aware power control scheme for dense 5G mobile communication system

The next generation mobile communication (5G) systems is targeting very high data rate by deploying more number of small cells, but this deployment results in high cross-tier interference because of using the same frequency band. To solve this challenge, an efficient power control scheme is desired specially for the case of uplink scenario. Thus, to solve this challenge, we propose the neighbors’ interference situation-aware uplink power control (IA-ULPC) scheme to reduce the cross-tier interference. In this scheme, we consider the interference situation of the neighbor cells while controlling the power of the users. Moreover, we also derive the target signal-to-interference and noise-ratio (

UE-specific Interference-Aware Open-loop Power Control in 3GPP LTE-A uplink HetNet

P_0

Architecture and features for 5G mobile personal cell

P0) equation to dynamically adjust it based on the neighbors’ base station interference situation. We compare the performance of the proposed IA-ULPC with the conventional fractional power control scheme (C-FPC). The extensive system-level simulations are carried out to prove the validity of the proposed IA-ULPC scheme which almost doubles the user average throughput and also decreases the interference around 20% in dense two-tier heterogeneous network environment as compared to C-FPC.