QoS Priority-Based Mobile Personal Cell Deployment with Load Balancing for Interference Reduction between Users on Coexisting Public Safety and Railway LTE Networks

It is a common case in Public Safety Networks (PSNs) that a user equipment (UE) instead of a base station (BS) acts as the multicast transmitter. In the network physical (PHY) layer, we adopt the fountain coding method to reduce network burden and energy consumption of UEs. However, current LTE standards support Quality of Service (QoS) controls only for unicast communications. To satisfy the QoS requirements of emergency group communications, an effective opportunistic multicast scheduling scheme is investigated at the MAC layer which can minimize the delay of a multicast. To further improve multicast throughput, Device-to-Device (D2D) relaying technique is also integrated into the proposed multicast scheduling scheme, which can combat the multicast bottleneck when one or very few receivers are with very poor channel conditions. The simulation results verify the effectiveness of the proposed D2D relaying based multicast service in LTE based PSNs.

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.

In this paper, we propose an energy efficient user association scheme for uplink heterogeneous networks with machine-to-machine (M2M) and human-to-human (H2H) coexistence. A group based random access protocol is designed for massive number of machine-type-communications (MTC) user equipments' (UEs) transmissions. A user association problem for UEs' energy efficiency maximization is formulated considering the HTC UEs' quality of service (QoS) guarantees and load balance among multiple BSs, simultaneously. A distributed iterative algorithm is developed to solve the optimization problem. In addition, the convergence of the proposed algorithm is proved. Simulation results show that our proposed scheme outperforms other schemes in terms of energy efficiency and QoS guarantees.

Cell outage compensation is a crucial way for public safety network (PSN) to recover network communication independently during disasters. As a significant technology for 5G, a cloud-radio access network (C-RAN) plays an important role in a PSN. C-RAN can better achieve multi-cell cooperative outage compensation under dense network coverage because of the characteristics of densification and centralization. Therefore, we propose an efficient multi-cell cooperative outage compensation convergence for the scene where more than one radio remote units (RRUs) are destructed in C-RAN-based PSN. This scheme compensates the network using both cooperative transmission and power adjustment. First, RRUs are selected to participate in the compensation according to the topology structure. Then, the problem model is built aiming at optimizing system outage probability. At the same time, the constraints of resources and service quality are considered. In addition, an enhanced immune-genetic algorithm is proposed innovatively to solve this NP-hard problem and to get the results of RRU transmit power parameters. Finally, simulation results demonstrate that the proposed algorithm convergences rapidly and our scheme reduces the PSN system outage probability effectively with the guarantee of users received power and the restriction of interference effects. The outage probability of the PSN system using the proposed method is 17.8% of the only cooperative transmit method and 3.9% lower than the only adjust power method.

In this article we offer visual depictions and analysis of contextual factors relative to the presence of public safety networks (PSNs) in the United States (US). A PSN combines shared technological infrastructures for supporting information sharing, computing interoperability and interagency interactions involving policing, criminal justice, and emergency response. The broad research objective is to explain the formation of PSNs based upon factors derived from rational choice and institutional theories. To do so we develop maps to represent our data analysis. This analysis suggests that our approach is promising for generating insights about PSNs and, by extension, about other types of inter-organizational collaborations focusing on using information and communication technologies to enable information-sharing.

Public protection and disaster relief (PPDR) agencies rely on wireless communications to respond in the event of emergencies. Public safety networks (PSNs) provide the wireless network used by emergency services. PSN is used to support push-to-talk services with some data transmission by employing land mobile radios. However, PPDR agencies are increasingly relying on additional information such as videos that require higher bandwidths. Therefore, many countries are transitioning or integrating their public safety networks with advanced broadband wireless communication systems such as fourth-generation (4G) long-term evolution (LTE) and planning to evolve to fifth-generation (5G) new radio (NR) in the future. The paper investigates infrastructure sharing mechanisms and deployment strategies in the transition of PSNs to a 4G LTE network, including a roadmap for cost analysis. Additionally, the paper examines LTE-based PSN deployment scenarios in various countries and engages in a discussion of the advantages and disadvantages of different sharing mechanisms and coexistence schemes. Finally, the challenges within the Public Safety Broadband Network (PSBN) are addressed and potential future research directions in this domain are deliberated.

Public safety incidents typically involve a significant amount of group traffic and have a stringent requirement of connection reliability. Hence multicast could potentially improve network and user performance significantly, which triggered our study on Long-Term Evolution (LTE) Multicast Broadcast Single Frequency Network (MBSFN). In this paper, we first derive a realistic MBSFN Signal-to-Interference-plus-Noise Ratio (SINR) analytical model, with multiple antennas, multipath channel, and equalizer considered. Then through comprehensive system level simulations, we compare MBSFN and unicast in terms of resource efficiency v.s. throughput, as well as outage probability. We also study the impacts of MBSFN size and quantify the MBSFN SINR improvement due to diversity combining and interference reduction, respectively.

Critical and public safety operations require real-time communication from the incident area(s) to the distant operations command center going through the evacuation and medical support areas. Data transmitted throughout such type of network is extremely useful for decisions makers and operations' conducting. Therefore, any delay in communication may cause lives' loss. Above all, the existing infrastructure communication systems (PSTN, WiFi, 4/5 G, etc.) can be damaged and is often not available solution. An alternate option is to deploy autonomous tactical network at unpredictable location and time. However, in this context there are many challenge especially how to effectively rout or disseminate the information. In this paper, we present behavior of varied multi-hops routing protocols evaluated in a disaster-simulated scenario with different communication technologies (i.e. WiFi IEEE 802.11; WSN IEEE 802.15.4; WBAN IEEE 802.15.6). Studied routing strategies are classified: Ad hoc proactive and reactive protocols, geographic-based and gradient-based protocols. To be realistic, we have conducted our simulations by considering a Mall in Doha city in the State of Qatar. Moreover, we have generated a mobility trace to model the rescue teams and crowd movements during the disaster. In conclusion, extensive simulations showed that WiFi IEEE 802.11 is the best wireless technology to consider in an emergency urban with the studied protocols. On the other hand, gradient based routing protocol performed much better especially with WBAN IEEE 802.15.6. Keyword: Tactical Ad-hoc Networks; Public Safety and Emergency; Routing Protocols; IEEE 802.11; IEEE 802.15.4; IEEE 802.15.6; Performance Evaluation I. Introduction Public safety is a worldwide governments' concern. It is a special continuous reactive set of studies, operations and actions in order to predict plan and perform a successful reaction in a disaster case. Coupled with the raise of number and variety of disasters, not only the economies and infrastructures are affected, but significant number of human lives. With regards to the emergency response to these disasters, the role of existing Public Safety Network (PSN) infrastructures (e.g. TETRA, LTE) is extremely vital. However, it is anticipated that, during and after the disasters, existing PSN infrastructures can be flawed, oversaturated or completely damaged. Therefore, there is a growing demand for ubiquitous emergency response system that could be easily and rapidly deployed at unpredictable location and time. Wherefore Wearable Body Area Networks (W-BAN) is a relevant candidate that can play a key role to monitor the physiological status of involved workforces and the affected individuals. Composed by small and low-power devices connected to a coordinator, WBAN communication architecture relies on three levels: On-Body (or intra-Body), Body-to-Body (or inter-Body) and off-Body communication networks. In disaster scenarios, the network connectivity and data is a challenging problem due to the dynamic mobility and harsh environment [1]. It is envisioned that, in case of unavailable or out-of-range network infrastructures, the WBANs coordinators along with WBANs sensors can exploit cooperative and multi-hop body-to-body communications to extend the end-to-end network connectivity. The Opportunistic and Mobility Aware Routing (OMAR) scheme is an on-body routing protocol proposed in one of our earlier works [2]. A realistic mobility model is also a major challenge related to the simulations. To the best knowledge of the authors, no comparable study in disaster context is conducted by considering a realistic disaster mobility pattern. In this paper, we investigate varied classes of multi-hop Body-to-Body routing protocols using a realistic mobility modeling software provided by Bonn University in Germany [3]. The mobility pattern is exploited by the WSNET simulator as a mobility trace of the nodes moving during and after the disaster. Note here that individuals are considered mobile nodes in the scenario. In the conducted simulations, each iteration, one communication technology configuration is selected (i.e. WiFi IEEE 802.11; WSN IEEE 802.15.4; WBAN IEEE 802.15.6), then simulations are ran with the routing protocols (i.e. proactive, reactive, gradient-based and geographical-based). This strategy provides a vision not only on the behavior of the routing protocols in the disaster context, but evaluates the communication technologies in such case also. For proactive, reactive, gradient-based and geographical-based routing protocols, Optimized Link State Routing protocol version 2 (OLSRv2) [4], Ad-hoc On-Demand Distance Vector (AODVv2) [5], Directed Diffusion (DD) [6] and Greedy Perimeter Stateless Routing (GPSR) [7] protocols are selected respectively The remainder of this abstract is organized as follows. In section II, we present briefly the disaster scenario considered. In section III, we explain the results of the simulations. Finally, in Section IV, we conclude and discuss perspectives. II. Landmark disaster scenario we are investigating a disaster scenario (fire triggering) in the “Landmark” shopping mall. The mobility model used is generated by the BonnMotion tool. We assume that the incident is caused by fire into two different locations. Rescuers are immediately called to intervene. We consider that firefighters are divided into 3 groups of vehicles with 26 firefighters in each group. Medical emergency teams that probably could reach the mall just after the incident, are consisting of 6 ambulances with 5 medical staff in each ambulance (30 rescuers in total). Civilians could also help rescuers and they are also considered in the mobility trace generation. Injured individuals are transported from the incident areas to the patients waiting for treatment areas to get first aids. Then, they will be transported to the patients clearing areas where they will be either put under observation or evacuated to hospitals by ambulance or helicopter. A tactical command center conducting the operations is represented by WSNET is an event-driven simulator for wireless networks. WSNET is able to design, configure and simulate a whole communication stack from the Physical to the Application Layer. We benefit from these features to vary the payload with the selected MAC and routing layer in each iteration. These combinations provided a deep review on the possible communication architecture to consider in disaster operations. The following section describes the outcome of these extensive simulations. III. Performance evaluation The main difference between the disaster and any other scenario is the emergency aspect. All flowing data in the network is considered highly important. The probability of packets that did not reach the destination must be zero. For this reason, our evaluation is regarded to the Packet Reception rate (PRR). Likewise, a delayed packet is such like an unreceived packet. That's why we consider the delay as decisive factor. Similarly, the energy consumption is also observed. The following table summarizes the obtained results. In terms of average PRR, WiFi IEEE 802.11 is convincingly better than the two counterparts combined with all the routing protocols. GPSR has a considerable PRR with WBAN IEEE 802.15.6, but the location information of the nodes is considered as known. Regarding the delay, DD is particularly efficient with WiFi and WBAN. To conclude, DD is an efficient routing protocol to consider in case of Indoor operations, while GPSR is most relevant in Outdoor operations where locations can be obtained from GPS. IV. Conclusion Disasters are growing remarkably worldwide. The existing communication infrastructures are not considered a part of the communication recuing system. Consequently, to monitor deployed individuals (rescue teams, injured individuals, etc.) data should be forwarded throughout these individuals (WBANs) to reach a distant command center. In order to evaluate the performance of diverse multi-hop routing protocols, we have conducted extensive simulations on WNSET using a realistic mobility model. The simulations showed that all evaluated routing protocols (i.e.AODVv2, OLSRv2, DD and GPSR) has the best PRR with the WiFi technology. While, DD was found to be the most efficient with the WBAN technology. GPSR also could be considered when the location information is available. Acknowledgment The work was supported by NPRP grant #[6-1508-2-616] from the Qatar National Research Fund which is a member of Qatar Foundation. The statements made herein are solely the responsibility of the authors.

Ultra dense network of small cells (SCs) was introduced to support high data rate services and increase network capacity. Owing to user equipment (UE) mobility and limited coverage of SCs, the load across a SC network recurrently becomes unbalanced. Such unbalanced loads result in performance degradation of network in terms of throughput, inefficient utilization of network resources and link failure. This paper proposes and evaluates a novel load balancing methodology based on UE-SC association, which incorporated two main factors:(i)load of SCs in UE’s neighborhood (ii)the received Signal to Interference and Noise Ratio (SINR)/Channel Quality Indicator (CQI) and Quality of Service (QoS) requirements of user. The proposed algorithm ensures that the standard deviation of load in SCs in the neighborhood of a given UE remains minimum when the UE is associated to a potential SC. Consequently, achieving load balancing among SCs proactively while maintaining high SINR/CQI levels for UE, with each UE-SC pairing. System-level simulations show that the proposed algorithm provides a more balanced load across network, which is quantified by a smaller standard deviation of load across the SCs and higher network throughput when compared to other load balancing algorithms.

This chapter provides an overview of economic and financial considerations for deploying a critical communications system, including general cost and financing related components and the alternative financing forms. It focuses on the public safety networks used by public safety agencies, which could be local, regional, or nationwide. Deploying a public safety network requires substantial financial investment. Financing a nationwide public safety network must address the initial investment mostly involving Capital Expenditures (CAPEX) and perhaps, more importantly, the ongoing Operational Expenditures (OPEX). The chapter provides a brief discussion on three popular financing alternatives: bond financing, lease financing, and financing via sharing the network. There are several mathematical methods to evaluate the economics of a given project. The chapter also provides a comparison of the methods, which need to be carefully evaluated and integrated as much as possible to maximize the benefits and minimize the cost of the proposed project.

Device-to-device communication, as provided by the third generation partnership project standardization, can play a vital role in designing a reliable pervasive public safety network, which allows the user equipment (UEs) to communicate directly with each other in emergency situations. In this paper, we analyze the performance of direct discovery, one of the features introduced by proximity services. This is examined in heterogeneous environments using the OpenAirInterface open-source software and USRP hardware platform. The experimental results highlight the suitable values for different gains and frequencies of the UEs for performing reliable baseline direct discovery in out-of-coverage scenarios. We evaluate the performance of direct discovery in terms of reliability and maximum range in outdoor and indoor scenarios. Furthermore, we propose a context-aware energy-efficient heuristic algorithm for direct discovery with the aim of extending the network lifetime in emergency scenarios. This heuristic yields significant improvements in UE lifetime (20-52%) and reduces redundant transmissions of discovery messages compared to the baseline approach.

With picocells deployed in the coverage of a macrocell in heterogeneous networks (HetNets), the macrocell evolved NodeB (MeNB) may receive interference signals from the picocell users, which results in more severe co-channel interference (CCI) problem in the uplink. In this paper, the spatial uplink interference coordination is investigated in multiple antenna systems, according to which the receiver coding matrix is generated by MeNB to mitigate the CCI from picocell users. Two interference coordination (IC) schemes are proposed based on whether the receiver coding matrix is full rank or not, named as full coding (IC-FC) and part coding (IC-PC), respectively. The application of the proposed schemes is discussed in single picocell and multiple picocell scenarios. The CCI can be totally canceled in single picocell scenario, and an algorithm is developed in multiple picocell networks to mitigate the most severely interfering picocell. Link level and system level simulations are applied, and it is shown that significant performance gain is achieved by our proposed schemes over traditional IC receivers.

Keeping First Responders (FR) connected has the highest priority of communications in public safety networks. In this paper, we propose a method to quickly determine where to deploy Edge-Devices for connecting the first responders in the scenarios, where the infrastructure supports may be insufficient. As an FR can only carry very few numbers of edge-devices, our research goals are two folds: (i) Quickly decide where to deploy edge-devices and (ii) deploy as less number of edge-devices as possible. We model the problem as an Optimal (Minimal) CDS construction problem with time constraints. Specifically, we propose a novel real-time connected dominating set (CDS) construction algorithm for connecting first responders (FRs) in public safety networks. The proposed algorithm is a polynomial time approximate solution that can yield a solution in a given time, which is guaranteed by both the algorithm convergence speed and the designed stopping theory based rules. The approximation ratio to the optimal solution is jointly determined by the stopping rules, the required time, and the algorithm properties. The outputs from the algorithm can guide the FRs to deploy and/or select edge-devices in off-network environments to make them connected.

With the proliferation of smart devices, machine-to-machine communication, and wearable, data and traffic is increasing enormously. Ultra-densification has been considered a promising technique to achieve substantial advantages in capacity, data rate, and coverage. However, the extensive deployment of devices to support huge data traffic results in high interference and energy issues. This is due to the unplanned deployment of small cells with varying power and coverage. Due to small coverage, users will frequently be changing associations with the base station. In this regard, user association plays a critical role in interference management, load balancing, energy consumption, and spectral efficiency. This paper proposes an energy-efficient load-aware user association technique, which assists the user equipment in selecting an optimal base station. The proposed technique leads to a stable user association considering load (traffic) while improving energy efficiency. The proposed user association operation ends when all user equipment gets associated with base stations by achieving the equilibrium state. Simulation results show that the proposed user association scheme outperforms significantly in load balancing, sum rate, and energy efficiency compared to max-SINR based user association.

Resilient Smart Grids require very robust communication infrastructures, which allow to support the control of the Smart Grid even and especially in critical situations. Current network quality assurance processes, such as drive tests in wireless systems, typically focus on cell coverage and quality of service parameters (e.g., max. data rate) at a specific geographical position, without considering the impact of overload situations. Therefore, this paper introduces a methodology for stress testing a communication infrastructure for Smart Grids by synchronized, distributed so-called Smart Traffic Generators (STGs). Due to their low cost, the STGs become a permanent part of the infrastructure and enable a network operator independent, continuous network quality monitoring. A case study leveraging a LTE deployment demonstrates how the proposed approach can prove the fulfillment of Quality of Service (QoS) requirements of time critical Smart Grid applications, even in stress situations with high cell load. Although, the proposed approach has been introduced for Smart Grids, it can also be used for ensuring the communication resilience for other critical infrastructures, e.g., public safety networks.