Broadcast Range Research Articles

Limiting the Broadcast Range of a Secreting Cell during Intercellular Signaling Using Protease-Mediated Degradation.

Synthetic biology is revolutionizing our approaches to biocomputing, diagnostics, and environmental monitoring through the use of designed genetic circuits that perform a function within a single cell. More complex functions can be performed by multiple cells that coordinate as they perform different subtasks. Cell-cell communication using molecular signals is particularly suited for aiding in this communication, but the number of molecules that can be used in different communication channels is limited. Here we investigate how proteases can limit the broadcast range of communicating cells. We find that adding barrierpepsin to Saccharomyces cerevisiae cells in two-dimensional multicellular networks that use α-factor signaling prevents cells beyond a specific radius from responding to α-factor signals. Such limiting of the broadcast range of cells could allow multiple cells to use the same signaling molecules to direct different communication processes and functions, provided that they are far enough from one another. These results suggest a means by which complex synthetic cellular networks using only a few signals for communication could be created by structuring a community of cells to create distinct broadcast environments.

A Novel High-Speed Data Encryption Scheme for Internet of Medical Things Using Modified Elliptic Curve Diffie–Hellman and Advance Encryption Standard

The security of data in an IoT network is of utmost importance. The medical IoT devices need to implement the security protocols in the devices to safeguard the crucial information. This paper proposes a novel high-speed data encryption scheme using elliptic curve cryptography (ECC) for key generation, key length reduction, Diffie–Hellman key exchange, SHA-256 and advance encryption standard (AES). The proposed hybrid data encryption scheme begins with elliptic curve key generation. Each authorized user in the broadcast range generated a private key using ECC. The proposed key reduction algorithm reduces the size of the secret key generated. This key is exchanged efficiently between the broadcast members using Diffie–Hellman key exchange. Each user then generates their final encryption keys. These keys are encoded using SHA-256 algorithm for further security. These keys are then used to encrypt the data using AES algorithm and sent to the cloud. The intended receivers can check the identity of the sender and decrypt the data using their own keys. The proposed method also includes user identity authentication. The origin of the message is verified to authenticate the sender of the message. This implementation is apt for home automation applications where data collected by medical devices like Fitbit and watches need to be shared among multiple users. The proposed method is at par in providing security to the data in much less time. The throughput, key generation time, key length, encryption time, decryption time and memory usage, Avalanche effect are efficient in comparison to existing methods.

Ethereal Resistance: Radio, Borders, and Dictatorship in the Southern Cone, 1960s-1980s

Like most authoritarian regimes, the military dictatorships that ruled over the Southern Cone nations of Uruguay, Argentina, and Chile sought to control media messaging and restrict access of citizens to alternative and/or anti-regime media. With its higher technical requirements and shorter broadcast range, television was relatively easy for state authorities to control. Radio was a different story, however. Not only was it possible—albeit dangerous—for regime opponents to emit clandestine broadcasts on occupied or unoccupied national frequencies, listeners could tune in to foreign stations to hear uncensored news reports, the voices of exiles, and messages of resistance and encouragement.

Secure Communication Channels Using Atmosphere-Limited Line-of-Sight Terahertz Links

Terahertz wireless links offer great promise for realizing physical-layer security due to the high directionality and the high path loss. In this work, we investigate the resilience against eavesdropping attacks in a directional terahertz link which exploits the attenuation due to the water vapor absorption resonances for enhanced security. The magnitude of the atmospheric attenuation can be controlled by tuning the carrier frequency relative to the peak of a water vapor absorption line. This idea can be used to thwart an eavesdropper by restricting the broadcast range of the signal. We develop a channel model for an eavesdropping scenario in which an attacker is located along a line-of-sight link. We explore through both experiments and calculations the performance of the terahertz channel, as well as the tradeoff between performance and security. Our results demonstrate the feasibility of limiting the broadcast range by making use of atmospheric conditions, paving the way for a simple yet powerful physical-layer security protocol for the terahertz range.

Extended buffer zone algorithm to reduce rerouting time in biotelemetry systems using sensing

Mobile Adhoc Network (MANET) routing methods must deal with connection breakdowns caused by frequent node movement, measurement and a dynamic network topology. In these cases, the protocol must discover alternate routes. Rerouting time refers to the lag that happens during this retransmission. Researchers have proposed many ways to reduce rerouting period. One such technique is buffer zone routing (BZR), which divides a node transmission region into a safe zone adjacent to the node and a hazardous zone towards the end of the broadcast range. This technique, however, has rare gaps and restrictions, such as the ideal dimensions of the buffer zone, a rise in hop duration, network stress, and so on. This study offers a method to improve or expand buffer zone communication by grouping nodes inside the buffer zone into virtual zones based on their energy flat. When the routing decisions are made quickly, the energy consumption of the nodes is minimized. In the safe area of extended BZR, transfer time is reduced, and routing efficiency is increased. It solves issues in the present algorithm and fills holes in it, decreasing the time required for rerouting in MANET.

Optimal Adaptive Data Dissemination Protocol for VANET Road Safety Using Optimal Congestion Control Algorithm

Introduction: VANET is a mobile ad-hoc system (MANET) that concerns vehicle-to-vehicle and vehicle-to-infrastructure communication. Unique characteristics such as higher node speeds and restricted road topology extricate VANET from other MANETs. Messages between vehicles and roadside infrastructure in VANET is over short to medium range wireless technologies. Dedicated Short Range Communications (DSRC) is a RF technology-based standard that has been designed exclusively for automotive communications. Like most MANETs, data are broadcasted in VANETs through the exchange of messages between the nodes. The limited road topology unlike MANETs, executes a directional way to the message flow. It becomes important that the data to be transmitted in the most effective ways with less delay, due to higher node speeds and unbalanced connectivity among the nodes. Hence, propagating data to the intended node or region of interest is a unique problem in VANETs and requires incorporating effective techniques to disseminate data. Data broadcasted from a vehicle will be received by all the nodes within the broadcast range. The difficulty of data dissemination is hence related to propagating data, not within but beyond the transmission range of the sender. An intuitively simple way to disseminate data beyond the transmission range is through flooding. In flooding each node which receives the message would simply rebroadcast the message without any regard to its current position or any other factors. Thus, data are propagated beyond the transmission range when a node at the border of the broadcast range rebroadcasts the message. For effective broadcasting, each vehicle upon receiving a message would make a decision to rebroadcast the message depending on whether or not it is the farthest node in the transmission range. Thus, the decision-making ability of each vehicle on participating in the message propagation is dependent on its awareness of vehicles around it and determines the overall effectiveness of the technique used in disseminating data. Objective: To identify an optimal cluster head based on effective parameters to reduce Control Overhead messages in a collision based traffic network. Methods: The proposed system consists of two processes namely candidate selection and control OH message reduction. The candidate selection process is carried out by Chaotic Fish Swarm Optimization (CFSO) algorithm which consists of cluster formation and Cluster Head (CH) selection. The control OH messages are reduced by a Predictor based Decision Making (PDM) algorithm. Results: Based on the performance metrics such as success rate, redundant rate, collision rate, number of control OH messages, data propagation distance, data propagation time and data dissemination efficiency, the proposed system is evaluated. The results shows that the proposed system performs well than the existing system. Conclusion: In this paper, we have suggested an Optimal Adaptive Data Dissemination Protocol (OAddP) for VANET road safety. The proposed OAddP mechanism uses the Chaotic Fish Swarm Optimization (CFSO) algorithm to perform the clustering and uses a Predictor based Decision Making (PDM) algorithm for control overhead messages reduction.

Two-Hop Neighborhood Information Joint Double Broadcast Radius for Effective Code Dissemination in WSNs

With the development of software-defined network (SDN) technology, sensor nodes can update soft codes to enable themselves to have new functions so as to make wireless sensor network (WSN) full of new vitality. However, how to spread the new code to every node in the network quickly and energy-efficient is a challengeable issue. In this paper, a Two-hop Neighborhood Information joint Double Broadcast Radius (TNI-DBR) scheme is proposed to disseminate the codes in duty cycle-based WSNs in a fast and energy-efficient style. The main innovations of this paper are as follows. The TNI-DBR scheme makes full use of the unbalanced energy consumption of the sensor network in the process of data collection and doubles the broadcast radius in the area with redundant energy so that more nodes can receive the new code in one broadcast and the broadcast range is further, which can reduce the delay of code dissemination effectively. Different from the conventional code dissemination schemes that select broadcasting nodes according to the information of the one-hop neighbors, in the TNI-DBR scheme, an $O(n)$ two-hop neighbor information exchange algorithm is proposed to obtain the duty cycle information of the two-hop neighbors. The TNI-DBR scheme selects the best broadcasting nodes based on information in the range of two-hop neighbors to enlarge the number of active nodes and reduce the time required for code dissemination. Sufficient theoretical analysis and experimental results show that the TNI-DBR scheme can significantly optimize the performance of code dissemination. Compared to previous schemes, the delay of code dissemination can be reduced by 43.09%~78.69%, the number of broadcasts can be reduced by 44.51%~86.18%, and the energy utilization ratio is improved by about 24.5%.

Broadcast Range Performances for Random Access-Based Wireless Mutual Broadcast

The wireless mutual broadcast (WMB) sharing informative data among proximal nodes has been recently spotlighted as a key enabler for smarter and safer society. These WMB applications may require different intended broadcast coverage (BC) depending on their attributes, and this coverage is profoundly affected by mutual interference among nodes. In this regard, this letter investigates the BC in terms of the proximity between nodes [so called the broadcast range (BR)] under a stochastic geometry framework. Furthermore, it proposes the design principles to improve the performances for an intended BR.

A Key Exchange Approach for Proficient and Secure Routing in Mobile Adhoc Networks

<p>Mobile ad hoc networks (MANETs) are collection of wireless mobile devices with restricted broadcast range and resources. Communication is achieved by relaying data along appropriate routes that are dynamically discovered and maintained through collaboration between the nodes. Discovery of such routes is a major task, both from efficiency and security point of view. This paper presents a proficient and secure routing, based on asymmetric authentication using key exchange approach (KEA). The proposed mechanism ensures secure routing and quality of service in MANETs and minimizes the network overhead. The KEA mechanism can be effectively used to develop a new routing protocol for Mobile Adhoc Networks which will provide maximum security against all kinds of attacks. In this paper, KEA is compared with other secure routing protocols like EEACK, AODV, and ARIADANE, to evaluate the efficiency of KEA in Ad Hoc Networks. The empirical results shows that there is an increase of 20% packet delivery ratio and a reduction of 10% routing overhead.</p>

Secure Route Discovery for Dynamic Source Routing in Manets

Abstract Mobile ad hoc networks (MANETs) are collections of wireless mobile devices with restricted broadcast range and resources and no fixed infrastructure. Communication is achieved by communicating data along suitable routes that are dynamically discovered and maintained through association between the nodes. Discovery of such routes is a major task both from good organization and security points of view. Recently a security model tailored to the specific requirements of MANETs. A novel route discovery algorithm called endairA is also proposed together with a claimed security proof within the same model. In this paper we show the security proof for the route discovery algorithm endairA is malfunctioning and moreover this algorithm is vulnerable to a hidden channel attack. We also analyze the security framework that is used for route discovery and argue the compos ability is an essential feature for ubiquitous applications. We conclude by discussing some of the major security challenges for route discovery in MANETs.

Soft Computing: Fuzzy Logic Approach in Wireless Sensors Networks

The recent growth of communication and sensor technology results in the enlargement of a new attractive and challenging area-wireless sensor networks (WSNs). A network comprising of several minute wireless sensor nodes which are organized in a dense manner is called as a Wireless Sensor Network (WSN). Every node estimates the state of its surroundings in this network. The estimated results are then converted into the signal form in order to determine the features related to this technique after the processing of the signals. It’s high computational environment with limited and controlled broadcast range, processing, as well as limited energy. The embedded soft computing approach in wireless sensor networks is suggested. This approach means a grouping of embedded fuzzy logic and neural networks models for information processing in complex environment with unsure, rough, fuzzy measuring data. It is generalization of soft computing concept for the embedded, distributed, adaptive systems.

A Review of Artificial Immune System Based Security Frameworks for MANET

Mobile ad hoc networks (MANETs) are collections of wireless mobile devices that form a communication network with restricted broadcast range, limited resources and without fixed infrastructure. Routing is a critical function in multi-hop MANETs. At the same time, security in MANETs—especially routing security—presents a number of new and interesting challenges. Communication is achieved by relaying data along routes that are dynamically discovered and maintained through collaboration between the nodes. Advances in the field of artificial immune systems provide an opportunity to improve MANET security and performance. Artificial immune systems mimic the functionality of the human immune system wherein there is clear distinction between self and non self and this delineation is important in a MANET where there is no centralized management. The high level of protection provided to the human body by an evolved immune system can be applied as a security feature in MANET. The current security techniques proposed for MANET have varying degrees of success due to the dynamic nature of a MANET. This paper will review different strategies for the application of artificial immune systems to MANETs.

Power controlled fair access protocol for wireless networked control systems

Distributed networked control systems through wireless sensor and actuator networks have a tremendous potential to improve the efficiency of many large scale system. Designing a communication protocol that satisfies the stability and safety of networked control systems is a challenging task, because there is not yet a clear understanding of the interaction between communication and control layers in the overall system. In this paper, the main challenges to design a communication protocol for networked control systems are first clarified. Starting from these requirements, a power controlled fair access protocol is proposed where nodes send packets to their respective receivers within a broadcast range in the context of random access networks. The protocol design is based on a constrained optimization problem where the objective function is the information coverage of individual nodes subject to the state update interval constraint. The state update interval is the time elapsed between successful state vector reports derived from the networked control systems. A simple power control algorithm determines the transmit power of each node to satisfy their broadcast transmissions. A distributed channel access algorithm coordinates the channel access probability of individual nodes to achieve max---min fairness of the state update interval of a random access network. The proposed protocol is applied for a conflict detection and resolution of an air transportation system. Furthermore, the protocol is compared with the default MAC and TSMA protocol (Chlamtac and Farago in IEEE/ACM Trans Netw 2(1):23---29, 1994) under various scenarios. Simulation results indicate that the protocol significantly improves the information coverage while reducing the state update interval. The proposed algorithm converges very fast while meeting the heterogeneous requirement of networked control systems. It also guarantees fairness among various nodes compared to the default MAC and TSMA protocol. By improving the communication performance, the proposed protocol improves the control efficiency and meets the safety criteria for air transportation systems.

Multi-agent consensus under a communication–broadcast mixed environment

This paper addresses multi-agent control under an environment where both agent-to-agent communication and one-to-all broadcast are available. The problem studied here is a consensus problem for a pre-specified location, i.e. collecting the agents at a desired location in an n-dimensional space, with a limited communication range and an unlimited broadcast range, which is a nice example to be solved under the mixed environment. For solving this, we first introduce a concept of the connected agent group. Using this notion, the problem is reduced to a consensus problem for the group-to-group relation and that for the agent-to-agent relation in the groups, from which we derive a controller achieving the consensus with probability 1. Finally, the performance of the proposed controller is demonstrated by numerical simulation.

Vehicle density based forwarding protocol for safety message broadcast in VANET.

In vehicular ad hoc networks (VANETs), the medium access control (MAC) protocol is of great importance to provide time-critical safety applications. Contemporary multihop broadcast protocols in VANETs usually choose the farthest node in broadcast range as the forwarder to reduce the number of forwarding hops. However, in this paper, we demonstrate that the farthest forwarder may experience large contention delay in case of high vehicle density. We propose an IEEE 802.11-based multihop broadcast protocol VDF to address the issue of emergency message dissemination. To achieve the tradeoff between contention delay and forwarding hops, VDF adaptably chooses the forwarder according to the vehicle density. Simulation results show that, due to its ability to decrease the transmission collisions, the proposed protocol can provide significantly lower broadcast delay.

Continuous range k-nearest neighbor queries in vehicular ad hoc networks

A driver should constantly keep an eye on nearby vehicles in order to avoid collisions. Unfortunately, the driver often does not see nearby vehicles because of obstacles (e.g., other vehicles, trees, buildings, etc.). This paper introduces a novel type of query, called a continuous range k-nearest neighbor (CRNN) query, in vehicular ad hoc networks, and it presents a new approach to process such a query. Most existing solutions to continuous nearest neighbor (CNN) queries focus on static objects, such as gas stations and restaurants, while this work concentrates on CRNN queries over moving vehicles. This is a challenging problem due to the high mobility of the vehicles. The CRNN query has characteristics in common with continuous range (CR) and CNN queries. In terms of CNN queries, the proposed approach achieves the same goal as the existing solutions, which is to decide effectively on valid intervals during which the query result remains unchanged. The proposed scheme aims to minimize the use of wireless network bandwidth, the computational cost, and the local storage while preserving information on the continuous movement of vehicles within the broadcast range of a given vehicle. Extensive experimental results confirm the effectiveness and superiority of the proposed scheme in comparison with an existing method.

Coverage with k-transmitters in the presence of obstacles

For a fixed integer k≥0, a k-transmitter is an omnidirectional wireless transmitter with an infinite broadcast range that is able to penetrate up to k “walls”, represented as line segments in the plane. We develop lower and upper bounds for the number of k-transmitters that are necessary and sufficient to cover a given collection of line segments, polygonal chains and polygons.

Vehicle-to-Infrastructure and Vehicle-to-Vehicle Information System in Work Zones

This paper describes the architecture, functionality, and field demonstration results of a newly developed dedicated short-range communication–based vehicle-to-infrastructure work zone traffic information system with vehicle-to-vehicle assistance. The new system is portable and can automatically acquire important work zone travel information such as the travel time and the starting location of congestion and then relay this information to drivers approaching the congestion site. Such information can help drivers make informed decisions on route choice, prepare for upcoming congestion, or both. The authors had designed a similar system earlier; that system had limited congestion coverage and message broadcast ranges, but the new system can achieve a much longer broadcast range (up to a few tens of kilometers) and can handle much longer congestion coverage (up to a few kilometers) by incorporating vehicle-to-infrastructure communication assisted by vehicle-to-vehicle communication. The system requires only a single roadside unit to acquire traffic data by engaging the vehicles traveling on the road whether within or outside of its direct wireless access range. From the traffic data, the system estimates important traffic parameters such as travel time and starting location of congestion and periodically broadcasts this information back to the vehicles approaching the congestion well before they enter the congested area. The results from the field demonstration show that the new system can adapt to a dynamically changing work zone traffic environment and can handle much longer congestion lengths as compared with the previous system, which used only vehicle-to-infrastructure communication without vehicle-to-vehicle assistance.

An adaptive algorithm for connecting mobile ad hoc network to Internet with unidirectional links supported

The performance of Internet connectivity is degraded dramatically by blind rebroadcast of gateway discovery packets when obvious unidirectional links are ignored. To overcome this problem, an effective adaptive gateway discovery algorithm for connecting mobile ad hoc network to Internet with unidirectional links supported is proposed in this paper. On the basis of modification for ad hoc on-demand distance vector (AODV), through rebroadcasting the gateway discovery messages and gateway advertisement messages, both of which are extended with local connection information, unidirectional links are successfully removed from global route computations and Internet connectivity is simultaneously enhanced. Furthermore, an adaptive Internet working scheme is adopted to provide the best coverage of gateway advertisement according to dynamically adjusting broadcast range and sending interval of gateway advertisement messages in terms of network conditions. Simulation results show that the proposed hybrid Internet connectivity algorithm can provide better connectivity performance due to avoiding unidirectional links effectively with reasonable overhead.

Connectivity Statistics of Store-and-Forward Intervehicle Communication

Intervehicle communication (IVC) enables vehicles to exchange messages within a limited broadcast range and thus self-organize into dynamical vehicular ad hoc networks. For the foreseeable future, however, a direct connectivity between equipped vehicles in one direction is rarely possible. We therefore investigate an alternative mode in which messages are stored by relay vehicles traveling in the opposite direction and forwarded to vehicles in the original direction at a later time. The wireless communication consists of two ¿transversal¿ message hops across driving directions. Since direct connectivity for transversal hops and a successful message transmission to vehicles in the destination region are only a matter of time, the quality of this IVC strategy can be described in terms of the distribution function for the total transmission time. Assuming a Poissonian distance distribution between equipped vehicles, we derive analytical probability distributions for message transmission times and related propagation speeds for a deterministic and a stochastic model of the maximum range of direct communication. By means of integrated microscopic simulations of communication and bidirectional traffic flows, we validated the theoretical expectation for multilane roadways. We found little deviation of the analytical result for multilane scenarios but significant deviations for a single lane. This can be explained by vehicle platooning. We demonstrate the efficiency of the transverse hopping mechanism for a congestion-warning application in a microscopic traffic-simulation scenario. Messages are created on an event-driven basis by equipped vehicles getting into and out of a traffic jam. This application is operative for penetration levels as low as 1%.