Transmission Of Control Information Research Articles

Stability-Capacity-Adaptive Routing for High-Mobility Multihop Cognitive Radio Networks

In high-mobility cognitive radio networks (CRNs), the fast topology changes increase the complexity of the routing scheme. In this paper, we propose a novel CRN routing scheme that considers the path stability and node capacity. First, a realistic mobility model is proposed to describe the movement of highly mobile airborne nodes [e.g., unmanned aerial vehicles (UAVs)] and estimate the link stability performance based on node movement patterns. Second, we propose a CRN topology management scheme based on a clustering model that considers radio link availability, and the cluster heads (CHs) are selected based on the node degree level, the average number of hops, and channel switching from member nodes to the CH. Third, we propose two new common control channel (CCC) selection schemes based on the node contraction concept and the discrete particle swarm optimization algorithm. The intercluster control channels and gateways are selected from the CHs, considering the average delay of control information transmission between two CHs, as well as the total throughput of control channels. Finally, a novel routing scheme is proposed that tightly integrates with the channel assignment scheme based on the node capacity. Our simulation results show that our proposed CCC selection scheme has high throughput and small transmission time. Compared with other popular CRN routing approaches, our proposed routing scheme achieves lower average end-to-end delay and higher packet delivery ratio for high-mobility CRN applications (such as airborne surveillance).

Investigation on Downlink Control Channel Structure Using Cross-Carrier Scheduling for Carrier Aggregation-Based Heterogeneous Network in LTE-Advanced

Carrier aggregation (CA) is one of the most important techniques for LTE-Advanced because of its capability to support a wide transmission bandwidth of up to 100MHz and heterogeneous networks effectively while achieving backward compatibility with the Release 8 LTE. In order to improve the performance of control information transmission in heterogeneous networks, cross-carrier scheduling is supported, i.e., control information on one component carrier (CC) can assign radio resources on another CC. To convey the control information efficiently, a search space is defined and used in Release 8 LTE. In cross-carrier scheduling, the optimum design for the search space for different CCs is a paramount issue. This paper presents two novel methods for search space design. In the first method using one hash function, a user equipment (UE)-specific offset is introduced among search spaces associated with different CCs. Due to the UE-specific offsets, search spaces of different UEs are staggered and the probability that the search space of one UE is totally overlapped by that of another UE can be greatly reduced. In the second method using multiple hash functions, a novel randomization scheme is proposed to generate independent hash functions for search spaces of different CCs. Because of the perfect randomization effect of the proposed method, search space overlapping of different UEs is reduced. Simulation results show that both the proposed methods effectively reduce the blocking probability of the control information compared to existing methods.

Improving Route Selection Mechanism using Trust Factor in AODV Routing Protocol for MaNeT

hoc network comprises of mobile nodes that cooperate with each other using wireless connections to route both data and control packets within the network. They are characterized by the use of wireless links, dynamically changing topology, multi-hop connectivity and decentralized routing mechanism and decision- making. The performance of Ad-hoc On Demand Vector (AODV) protocols has been modified by including the source route accumulation feature. As low transmission power of each ad-hoc node limits its communication range, the nodes must assist and trust each other in forwarding packets from one node to another. However, this implied trust relationship can be threatened by malicious nodes that may fabricate, modify or disrupt the orderly exchange of packets. Security demands that all packets be authenticated before being used. A particularly hard problem is to provide efficient broadcast authentication, which is important mechanism for MaNet. In this paper, we propose a routing algorithm which adds a field in request packet which stores trust value indicating node trust on neighbour. Based on level of trust factor, the routing information will be transmitted depending upon highest trust value among all. This not only saves the node's power by avoiding unnecessary transmitting control information but also in terms of bandwidth (channel utilization), which is very important in case of MaNet. The malicious node can attack on the control packet and misbehave in the network .The malicious node, which may or may not be trusted node. In this paper, we use trusted path irrespective of shortest or longest path which can be used for communication in the network. We are able to calculate route trust value on the complete reply path which can be utilized by source node for next forthcoming communication in the network.

Study on the Features of English Political Euphemism and its Social Functions

Political euphemism is a tool for political leaders to control information transmission. Based on some examples, this paper begins with a summary of three features which distinguish political euphemism from others. Then, it discusses its two social functions based on Austin’s Speech Act Theory: 1. as political leaders’ tool, political euphemism plays the role of hiding the truth and legalizing wrong behaviors; 2. it influences people’s sense of right and wrong as well as their understanding of the objective world, hence succeeding in persuading them. Such a linguistic phenomenon provides another proof that language is not only a reflection of the objective world but a process of social construction.

A study on Data Transmission Scheme for High Functional Railway Signaling System

Railway signaling systems that transmit control information via rails have been deployed in many applications, for example, digital automatic train control (ATC) systems for controlling train speed. Since the performance of digital ATC systems depends on the signal transmission speed, recently there have been many studies aimed at realizing high-speed data transmission. However, it is difficult to increase the transmission speed because rails have strong attenuation in proportion to an increase of the frequency. In this paper, we aimed to increase the transmission speed by improving the modulation scheme to overcome these limitations. We proposed CDMA-QAM method that is combined code-division multiple access (CDMA) and quadrature amplitude modulation (QAM). And we evaluated in a field trial the CDMA-QAM rail transmission device developed using DSP. On the other hand, an analog ATC based on an amplitude modulation (AM) is still employed in some railway lines. It is difficult for their lines to introduce the digital signal due to track circuit configurations and interoperability conditions. So we studied a data transmission scheme that makes it possible to mix an analog signal and a digital signal, and evaluated the influence given to both signals using a developed device that generates the mixed signal of analog and digital signal.

Control information transmission without resource consumption for PAPR reduction of OFDM signal

A peak-to-average power ratio (PAPR) reduction method for orthogonal frequency division multiplexing (OFDM) signals is proposed that requires no additional resources to transmit side information. The approach used to reduce PAPR is based on selected mapping (SLM). SLM produces several candidates of OFDM symbols, the subcarrier phases of which are rotated, and the OFDM symbol that yields the minimum PAPR is selected and transmitted to the receiver. To cancel the rotation used to generate the original signal at the receiver, transmission of side information using a time slot is usually required. This decreases the efficiency with which data can be transmitted. The proposal is to modify SLM so as to implant the side information into the OFDM data symbol. This results in no efficiency loss. Additionally, the error rate in estimating the side information is extremely low when enough subcarriers are used to carry the side information. The performance of the method is confirmed by numerical simulation. The PAPR improvement equals that of the original SLM. The implanted side information was transmitted with high reliability.

Cooperative search versus random search using UAV swarms

We analyze and compare the performance of two rival search strategies for agents searching for moving, evasive targets. One strategy is a cooperative search plan that integrates the multiple agents—unmanned aerial vehicles (UAVs) with sensors—into an advantageous formation that enhances thedetection probability while minimizing the transmission of control information for maintenance of the team topology. The second strategy employs cheaper UAVs that search independently. The performance of the two strategies is compared interms of the probability of detection and time to first detection.

A new header compression scheme for TCP streams in IP based wireless networks

AbstractThe current trend in the telecommunication world is the proposal of a universal telecommunication system deriving from the convergence between mobile telephony and data transmission. To achieve such a convergence in an efficient way, it is presumably necessary to utilize a network platform totally based on TCP/IP architecture (an ‘All‐IP Network’). However, the encapsulation process of TCP/IP wastes a substantial part of the radio channel bandwidth for the transmission of control information (header) that does not have any specific function at radio level. Since this bandwidth is generally the most expensive and limited resource for wireless networks, it is necessary to adopt a header compression scheme that can reduce the protocol overhead while working efficiently and robustly under noisy links with time‐variant BER conditions. In this paper, a new header compression scheme for TCP streams as a specific header compression profile within the IETF ROHC (robust header compression) framework is proposed and analyzed through simulations exploiting network simulator (ns‐2). The proposed scheme, compliant with IETF requirements for TCP/IP header compression, is based on the distinct management of data and acknowledgment (ACK) streams associated with the TCP connection and exploits a robust header encoding technique for reducing the effect of error propagation. The results obtained, in terms of throughput, overhead and goodput, are reported as a function of bandwidth and BER. A comparison with the results obtained without compression allows us to evaluate the performance of the proposed compression scheme in a realistic and dynamic environment. Copyright © 2004 AEI

Power and Information Transmission to Implanted Medical Device Using Ultrasonic

Using ultrasonic, we propose here a novel method of transmitting power and information to implanted medical equipment. The proposed system is composed of two piezo oscillators and has the following functions: transmission of power and control information to an implanted device, and transmission of the information acquired by an implanted device to the outside of a living body. With amplitude shift keying (ASK), 9.5 Kbps is obtained for the proposed information transmission system.

Efficacy of floor control protocols in distributed multimedia collaboration

Distributed multipoint applications for group interaction across wide-area networks, such as for simulation and telecollaboration, are becoming increasingly popular. While reliable multicasting has made significant advances in recent years, effective mechanisms to synchronize and coordinate work within large multicast groups and across long distances are still lacking. Synchronous sharing of resources, whose operational semantics prohibits parallel usage, typically creates race conditions among users, which can be resolved through an access discipline called floor control. Existing solutions on floor control, implemented either at the session or application layer, are mostly proprietary, limited in scope and not scalable. Furthermore, no performance comparison of floor control protocols has been attempted to date. We present a novel taxonomy and comparative performance analysis of known classes of floor control protocols, ranging from socially mediated control to protocols operating on ring and tree topologies. We find that aggregation and selective transmission of control information in a tree structure is the most promising solution with regard to scalability, efficacy, and robustness. The principal operation of such a tree protocol is outlined, which dynamically organizes participants in a multi-level control tree and aggregates resource sharing directives on the paths between interacting stations.

MOSAIC: a multiwavelength optical subcarrier multiplexed controlled network

The experimental demonstration of MOSAIC, a reconfigurable WDM add/drop network with subcarrier multiplexed control, is presented. The MOSAIC network implements the optical layer protocol to support bit-rate transparent multichannel lightpaths. Two types of add/drop multiplexers are implemented and combined in a three-node experiment. Multihop lightpaths are established giving an end-to-end bit error rate of better than 10/sup -9/ at 1.2 Gbps. The reconfigurable add/drop multiplexer is based on a novel dilated 2/spl times/2 acoustooptic filter switch crossconnect and an analog optoelectronic crossconnect that drives a ten-wavelength laser array transmitter up to 2.5 Gbps per wavelength. The fixed wavelength add/drop multiplexer utilizes a fast digitally tunable laser transmitter. Both add/drop multiplexers support bit-rate transparent 2R optoelectronic regeneration as well as wavelength translation. Subcarrier multiplexing on each wavelength is used to support channel state monitoring and channel equalization as well as transmission of digital network control information. Systems experiments demonstrate cascaded 2R optoelectronic regeneration with wavelength translation and cascaded multichannel optical switching with up to seven hops. It is shown that combining cascaded 2R optoelectronic regeneration with cascaded multichannel optical switching can be used to balance jitter accumulation and amplified spontaneous emission generated amplitude noise to yield high signal-to-noise ratio for lightpaths.

Information metabolism as a model of consciousness.

Kepinski's model of "information metabolism" is a biological model which is based on the structural organization of the cell and which attempts to describe information processing in analogy to energy metabolism. The terms of control center, information transmission and transformation, energy requirements and boundaries are considered. The principles of this model are explained. The original model is extended by addition of an integrated model of the main states of consciousness and a developmental model of information metabolism. Concepts of protective mechanisms of information metabolism are developed.

Blank and burst transmission of data over active speech channels

To increase the capacity of blank and burst transmission of control information in cellular communication systems, the authors explore the application of a speech segment reconstruction technique. The transmitter selects a blanking interval on the basis of a segment classification measure, while the receiver replaces the missing speech with an estimate based on previously received speech. Using this approach, approximately 3.2 data bursts per second, each lasting 16 ms may be sent without degrading speech quality.

Dynamic Scheduling Protocols for a Multiple-Access Channel

In this paper the multiple-access problem in a packet network is considered. A finite number of independent, packet transmitting users is assumed. Protocols are developed to allocate the channel resources among the users. Part of the channel capacity is assigned to control information. This information is used to make probabilistic inferences of the queue lengths and delay characteristics of the users. The probabilistic inferences are used to develop dynamic scheduling protocols for data transmission. Protocols are developed for two different levels of control information. An analysis of the relationship between amount of control information and system performance is carried out, and a study of the frequency of transmission of control information is also provided.

Water Line Transmission of Control Information

The hydrodynamic relations of flow and pressure are used to transmit information over a ten mile long, small diameter transmission main. The system includes an inlet rate of flow controller on the terminal reservoir, so designed that the rate of inflow into the reservoir is dependent only on the level of the water in the reservoir, and will not normally be affected by the pressure in the transmission main. Selection of the well pump being used is determined by the rate of flow of the water into the reservoir. The output pressure of the pump is regulated by varying the speed of the engine driving the pump. The engine speed is controlled by a preselected head-discharge relationship of the transmission main, and is controlled in such a manner that the pressure on the control valve at the reservoir inlet will be between 20 and 40 psi. The entire system operates with only an occasional checking or mechanical service call.

Remote Control of TV Microwave Equipment

Recent actions by the FCC have made it possible for privately owned and operated microwave links to be constructed by television stations. The need for remote control of the systems has brought about the development of some novel techniques for input switching, system reversal, and the transmission of control information. Hardware designed for these functions will be described.

Syncroscan: A high-speed control system for railway signaling

The Syncroscan <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> system, a new approach to the problem of centralized traffic control, retains relay coding equipment, with its inherent reliability, for transmitting control information to the field. In addition, it uses an electronic scanning system to provide the speed and capacity necessary to report up-to-the-moment information from hundreds of miles of railroad.