Distributed wireless channel allocation in networks with mobile base stations

In traditional cellular networks with fixed base stations, the channel reuse pattern is static and deterministic. When the cell layout is dynamic, due to the mobility of base stations, the cluster of cells within cochannel interference range changes with time. Consequently, the channel reuse pattern is highly dynamic. Moreover, base stations also need wireless channels to communicate amongst themselves. A communication session between a pair of nodes may have to switch channels due to the movement of other nodes into the neighborhood. None of the existing dynamic channel allocation algorithms for cellular networks works in such a system. Hence, there is a need for new wireless channel allocation algorithms for virtual cellular networks with mobile base stations. In this paper, principles of mutual exclusion pertaining to distributed computing systems are employed to develop such an algorithm. The inter-base-station wireless links are referred to as backbone links, while the base station to mobile node links are referred to as short-hop links. The proposed algorithm is distributed, dynamic, and deadlock-free. Disjoint sets of channels are used for backbone and short-hop links. The distributed nature of the channel allocation scheme leads to scalability and robustness, as the responsibility is no longer centralized at the mobile telecommunications switching office (MTSO). Instead, it is shared among all the mobile base stations. In addition, the issue of channel rearrangement is addressed. Channel rearrangement is the switching of channels, performed to prevent cochannel interference, when mobile base stations using the same channels, hitherto not in interference range, come within the range of each other. If multiple channels are available to support a communication session, the channel selection policy can have a significant impact on performance. A random selection from the set of available channels yields better performance at low to moderate channel demand. This is in contrast to ordered channel selection (from one end of the spectrum), which always yields the best performance for cellular networks. Results obtained by simulating the algorithm are consistent with the theoretically obtained values.

This paper presents measurement and evaluation of radiation power density emitted from mobile cellular base stations in Abuja and it’s environ. Forty (40) mobile base stations with ten (10) each from AIRTEL, ETISALAT, GLO and MTN located in areas with high population were randomly examined across Abuja. Broadband analysis method was employed in the measurement of the radiation power density. The results obtained shows that most of the base stations recorded lower radiation power density below the safety standard value of 4.5watt/m2 , 22.5 watt/m2 for 900MHz frequency though few base stations recorded above standard value: GLO-BS02, GLO-BS03 and MTN-BS02 recorded 59.02 mW/m2, 39.76 mW/m2 and 46.70 mW/m2 respectively. The result also revealed that as distance increases, the mean power density reduces. This is to said that human exposure to radio frequency radiation have less or no health hazard at distance far away from the mobile cellular base station.

The ever-increasing number of mobile telecommunication base station as a result of increasing demand for broadband applications has raised a growing concern and worry over the health implications and safety of the radiations from these base stations by the resident of Ekiti State and Nigeria in Nigeria. Measurement of radio frequency was conducted in this research in order to study the electromagnetic field radiation level in Ekiti State Nigeria. Investigation was conducted with the four available mobile operators with the three sub-frequency band viz 900 MHz, 1800 MHz and 2100 MHz. The power density of radio frequency radiation was estimated through measurement with the aid of A 3-Axis RF Radiation Strength Meter TM-196 and Handheld Spectrum Analyzer Model NA-773, 144/430. The peak and average power density was computed using the method of theoretical calculation and the safety distance from the antennas were estimated. The measured and the calculated values were compared with the international commission on non-ionizing radiation protection (ICNIRP) standard for public and occupational exposure level. Results show that the radiations from the base stations adheres to the standard provided by ICNIRP

The aim of the present double-blind, sham-controlled, balanced randomized cross-over study was to disentangle effects of electromagnetic fields (EMF) and non-EMF effects of mobile phone base stations on objective and subjective sleep quality. In total 397 residents aged 18-81 years (50.9% female) from 10 German sites, where no mobile phone service was available, were exposed to sham and GSM (Global System for Mobile Communications, 900 MHz and 1,800 MHz) base station signals by an experimental base station while their sleep was monitored at their homes during 12 nights. Participants were randomly exposed to real (GSM) or sham exposure for five nights each. Individual measurement of EMF exposure, questionnaires on sleep disorders, overall sleep quality, attitude towards mobile communication, and on subjective sleep quality (morning and evening protocols) as well as objective sleep data (frontal EEG and EOG recordings) were gathered. Analysis of the subjective and objective sleep data did not reveal any significant differences between the real and sham condition. During sham exposure nights, objective and subjective sleep efficiency, wake after sleep onset, and subjective sleep latency were significantly worse in participants with concerns about possible health risks resulting from base stations than in participants who were not concerned. The study did not provide any evidence for short-term physiological effects of EMF emitted by mobile phone base stations on objective and subjective sleep quality. However, the results indicate that mobile phone base stations as such (not the electromagnetic fields) may have a significant negative impact on sleep quality.

Background: There have been claims of a potential link between radio frequency (RF) emissions from mobile phone stations and cancer. In addition, widespread public concern has been expressed about the placement of cell phone antennas due to concerns about the risk of cancer. Objective: The objective of the study was to assess the effect of mobile phone base stations on oxidant and antioxidant markers and to investigate its potential correlation with cancer progression. Methods: The study involved three groups: cancer patients, healthy individuals residing near mobile phone base stations, and a control group living away from such base stations. Results: The study revealed significant differences in most biochemical parameters among the groups, highlighting the impact of mobile phone base stations on health. Cancer patients residing near mobile phone base stations (Group 1) showed notable changes compared to healthy individuals living both near (Group 2) and far (Group 3, control group) from mobile phone base stations. Specifically, the harmful effects of mobile phone base stations were evident in the increased total oxidant status (TOS), decreased total antioxidant capacity (T-AOC), and altered liver enzymatic activities (AST, ALP, ALT, LDH). Conclusion: This study finding suggests that proximity to mobile phone base stations may negatively influence oxidative stress and liver function leading to cancer. Further research is necessary to fully understand these effects and develop appropriate public health strategies.

Mobile Backbone Wireless Networks (MBWN) [10] are wireless networks in which the base stations are mobile. Our strategy is the following: mobile nodes are dynamically grouped into clusters of bounded radius. In the very large wireless networks we deal with we deal with, several hundreds of clusters may be generated. Clustering makes use of a two dimensional Euclidean version of the Antipole Tree data structure [5]. This very effective structure was originally designed for finite sets of points in an arbitrary metric space to support efficient range searching. It requires only a linear number of pair-wise distance calculations among nodes. Mobile Base Stations occupy an approximate centroid of the clusters and are moved according to a fast practical bipartite matching algorithm which tries to minimize both total and maximum distance. We show that the best known computational geometry algorithms [1] become infeasible for our application when a high number of mobile base stations is required. On the other hand our proposed 8% average error solution requires O (k log k) running time instead of the approximatively O (k2) exact algorithm [1]. Communication among nodes is realized by a Clusterhead Gateway Switching Routing (CGSR) protocol [15] where the mobile base stations are organized in a suitable network. Other efficient clustering algorithms [11, 17] may be used instead of the Antipole Tree. However the nice hierarchical structure of the Antipole Tree makes it applicable to other types of mobile wireless (Ad-Hoc) and wired networks but this will be subject of future work.

This paper proposes an omnidirectional high-gain slot array antenna for mobile phone base station. The advantages of this proposed antenna are low profile, light weight, and easy fabrication and installation. Moreover, it provides not only the moderately high gain but also the omnidirectional pattern, which more appropriate for mobile phone base station. The half-power beamwidths in E-plane is around 24 degrees, while its radiation pattern is similar to the circle or omnidirection. The paper also presents the design procedures of a 1×4 array antenna using slot antennas associated with two side-wings for increasing its gain. A Computer Simulation Technology (CST) software has been used to compute the reflection coefficient (S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf> ), radiation patterns, and gain of this antenna. The bandwidth, at S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf> (−10 dB), is which can be well utilized for 3G base station, with a gain around 9 dB.

TCP is a reliable transport protocol tuned to perform well in traditional wired networks, where most packet losses are due to congestion. In wireless networks, however, packet losses result from wireless link loss in addition to congestion loss. Thus, TCP suffers a significant degradation in performance over wireless networks because it does not distinguish wireless link loss from congestion loss. To overcome this problem, the explicit wireless loss notification (EWLN) scheme is proposed to explicitly inform wireless link loss to the TCP sender. Previous work to deploy EWLN often lacked explicit specification of the interplay between EWLN and link-layer protocols, including error recovery mechanisms. In addition, many systems, or being based on computation demanding functionality of agents at a base station, were designed for the scenario where information is accessed from a mobile station through a wireless-to-wired connection. In this paper, we present an EWLN scheme that deploys the information from the MAC layer and takes into account the interplay with the error recovery mechanism at the link layer. The scheme does not require different implementations for mobile terminals and base stations and hence can support efficient TCP-based data transmission over wired-to-wireless and wireless-to-wired connections as well as ad-hoc networks. We also present EWLN-enabled TCP implementations which, showed significant improvements over the standard TCP-Reno and TCP-SACK protocols, as evidenced by simulation studies over ns-2 network simulator.

Wireless mobile communication networks have become essential for human life. A great booming and huge investments are devoted to develop the services without taking into considerations the health effect of electromagnetic radiations of the base stations concerning with these services. Base stations for wireless mobile communication have brought Electromagnetic Field (EMF) sources to the permanent residences of people. A global increase in the level of electromagnetic background has taken place leading to its continuing presence in the environment. Cellular mobile radio communications have developed rapidly in Egypt and are one of the most actively growing sectors of the national economy. Many studies were made in this field and they did not prove that there is no effect for the EMF radiated from the mobile base stations. So, in this paper a procedure will be proposed to calculate the safety distance that the human beings can exposure from macro-cell of mobile base station. An on field measurement has been done to confirm this safety distance.

An analytical space-time fading correlation for the multi-input-multi-output (MIMO) channel, as a function of antenna spacing, angle spread, and Doppler spread, is derived and is verified with deterministic simulations. We investigate the performance of the uplink spatial fading correlation of a MIMO channel. We consider four uniform circular array (UCA) elements at both mobile station and base station. The angle of arrival and the angle of departure at the base station and the mobile station are distributed by truncated Gaussian and uniform probability distribution function(s) respectively. For large values of N, the simulation and analytical results agree. The results show that spatial separation between antenna elements can be minimized at the base station by employing two or more antennas at the mobile station

Network designers expect a highly mobile, highly responsive, and quickly deployable network structure to enable communication in emergency situations. For this reason, a major research goal for emerging mobile network (mobile sensor network, mobile ad hoc network, etc.)is to achieve good coverage and robust communication performance by coordinated management of base stations or nodes. In this paper, we extend current methods to balancing cell load by taking base station mobility into account.We propose a novel distributed base station mobility strategy (DMS). We focus on a recently attractive network model where localized communication is supported by using mobile base stations (MBSs) placed on moving vehicles. In order to minimize the blocking rate in high traffic density area, the proposed strategy will lead the MBSs to suitable locations and re-share the whole traffic load. We demonstrate the convergence of this distributed mobility strategy by both theoretical analysis and numerical evaluations of realistic networks. The strategy enables each MBS to select destination efficiently and locally with limited information exchange. Compared with the traditional load balancing method based on transmit power control, the proposed algorithm has obvious advantages in reducing the dropped calls, especially with extremely uneven load distribution.

As for radio channel control of a cellular mobile communication system, location measurement is an important technique for determining the base station to be Connected with the mobile station. This paper describes the radio zone selection characteristic when a part of the control channel is time‐shared by base stations and the reception level of each base station is measured at mobile stations. MSSC (Multitransmitter Simul/Sequential Casting) of control channels is proposed, which improves the location measurement and is suitable for a high‐capacity system. The MSSC channel consists of simul‐cast parts and sequential‐cast parts. Its speech connection control sequence when applied to the cellular mobile communication system is shown. Next, the relation between the reception level variation characteristic in land mobile communication and the average reception level measurement accuracy when burst signals are received several times is studied. Both analytical results and laboratory experimental simulation results are shown. Finally, the zone selecting rate of a mobile station is calculated and the effect of the proposed control channel configuration is clarified.

Unmanned aerial vehicles (UAVs) can serve as mobile base stations (MBSs) to provide wireless communication for ground terminals (GTs). This paper proposes a novel polynomial-time method to place MBSs, in order to minimize the number of MBSs ensuring each GT is within the wireless coverage of at least one MBS. The proposed algorithm transforms the deployment problem of MBSs into a minimum clique partition problem with the minimum enclosing circle coverage constraint. Based on the distance between GTs and the coverage radius of MBSs, the algorithm constructs an undirected graph $G(V,E)$ to denote the adjacent information between GTs. In our algorithm, the GT with the minimum degree is given a higher priority to deploy MBSs, and the location of each MBS will be refined gradually to cover as many as possible GTs. Numerical results show that, in the case where there are no capacity constraints for MBSs, the proposed algorithm performs advantageously over other algorithms in terms of the required number of MBSs as well as runtime overhead. Besides, we also analyze the impact of the capacity constraint of MBSs on the number of required MBSs, and compare the proposed algorithm with the Edge-prior algorithm on the case with the capacity constraint, showing that our algorithm requires fewer MBSs especially when the capacity of MBSs is high.

Due to a tremendous increase in mobile traffic, mobile operators have started to restructure their networks to offload their traffic. New research directions will lead to fundamental changes in the design of future Fifth-generation (5G) cellular networks. For the formal reason, the study solves the physical network of the mobile base station for the prediction of the best characteristics to develop an enhanced network with the help of graph theory. Any number that can be uniquely calculated by a graph is known as a graph invariant. During the last two decades, innumerable numerical graph invariants have been portrayed and used for correlation analysis. In any case, no efficient assessment has been embraced to choose, how much these invariants are connected with a network graph. This paper will talk about two unique variations of the hexagonal graph with great capability of forecasting in the field of optimized mobile base station topology in setting with physical networks. Since K-banhatti sombor invariants (KBSO) and Contrharmonic-quadratic invariants (CQIs) are newly introduced and have various expectation characteristics for various variations of hexagonal graphs or networks. As the hexagonal networks are used in mobile base stations in layered, forms called honeycomb. The review settled the topology of a hexagon of two distinct sorts with two invariants KBSO and CQIs and their reduced forms. The deduced outcomes can be utilized for the modeling of mobile cellular networks, multiprocessors interconnections, microchips, chemical compound synthesis and memory interconnection networks. The results find sharp upper bounds and lower bounds of the honeycomb network to utilize the Mobile base station network (MBSN) for the high load of traffic and minimal traffic also.

A nationwide interoperable public safety broadband network is being planned by the United States government. The network will be based on long term evolution (LTE) standards and use recently designated spectrum in the 700 MHz band. The public safety network has different objectives and traffic patterns than commercial wireless networks. In particular, the public safety network puts more emphasis on coverage, reliability and latency in the worst case scenario. Moreover, the routine public safety traffic is relatively light, whereas when a major incident occurs, the traffic demand at the incident scene can be significantly heavier than that in a commercial network. Hence it is prohibitively costly to build the public safety network using conventional cellular network architecture consisting of an infrastructure of stationary base transceiver stations. A novel architecture is proposed in this paper for the public safety broadband network. The architecture deploys stationary base stations sparsely to serve light routine traffic and dispatches mobile base stations to incident scenes along with public safety personnel to support heavy traffic. The analysis shows that the proposed architecture can potentially offer more than 75% reduction in terms of the total number of base stations needed.