摘要:

AbstractThe digital cross‐connect system (DCS) employs cross‐connect equipment composing the synchronized digital network. The scale of DCS is enlarged using the rearranged‐type TST switches based on the nondisturbing rearrangement control algorithm.This paper considers the case where DCS is controlled using the proposed rearrangement pattern search algorithm. A control algorithm is proposed which can avoid the generation of a blocking state, thereby necessitating the rearrangement control, and can realize the nondisturbing rearrangement control when a blocking is produced. The effectiveness of the method is demonstrated by computer simulation.In this paper, knowledge in other studies such as the mechanism of block generation is summarized. Then an evaluation measure is introduced for the S switch state. A control algorithm is proposed which suppresses the generation of the blocking by selecting the S switch timeslot to maximize the evaluation measure. It was verified by the computer simulation that the generation of the rearrangement control is reduced by approximately 5 to 30 percent, depending on the switch structure, compared to the algorithm that minimizes the evaluation measure for the switch. A nondisturbing control method for the switch also is pres

ISSN:8756-6621    

DOI:10.1002/ecja.4410760101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper proposes a new multimedia message communication system. This system is strongly integrated with deskwork operation by multiple polymorphism of object‐oriented construction in a distributed computer resource OA environment consisting of networks, personal computers, and workstations.Here, a message communication system and desk‐work system are regarded as a means of processing mail with undecided/decided boxes as start/end points. Further, automated generation of an individual action schedule and response mail has been implemented by using a distributed coordination algorithm of 1:Nconversation element module with knowledgebase of individual action status, and its application to automated and personalized secretary work in OA environments has been stud

ISSN:8756-6621    

DOI:10.1002/ecja.4410760102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIntensive research and development efforts have been made on the intelligent network (IN) to realize diversified and advanced telecommunication services and the early introduction of new services under a multi‐vendor environment.Earlier research and development, however, assume the conventional telephone service and narrowband ISDN services and gave little consideration to the broadband ISDN.The study of the IN from the viewpoint of the broadband ISDN is urgent considering the systematic realization of the services (i.e., multimedia services) that are not yet sufficient as well as the increase of the demand for the development of new services.This paper proposes the call model, which provides the basis for realizing the IN architecture incorporating the broadband ISDN. First, the basic concepts are defined clearly. Then the call model is proposed which can realize the general connection control for various connection types as well as the flexible control for the multiple virtual channels in the multimedia environment. The model also facilitates the control of the interactions among related services. Finally, the service control characteristics of the proposed call model are investigate

ISSN:8756-6621    

DOI:10.1002/ecja.4410760103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe intelligent network (IN) is expected to play an important role in rapidly and efficiently introducing new telecommunication services. This, paper discusses the abstraction and control methods for constructing a service control environment in the intelligent network which does not depend on specific service. By using this method, a real network configuration is abstracted into several patterns, considering the control points required by each service specification and each pattern can be described as a combination of functional virtualized resources.It is made possible to handle the diversified service specifications in a unified way which is independent of detailed conditions of the transport network. It is made possible also to ensure the service independency of the control interface specifying the interface by control of each virtualized resources. Moreover, a model for the call control is proposed and the function assignment in introducing IN into existing network is discussed.

ISSN:8756-6621    

DOI:10.1002/ecja.4410760104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractCommon channel signaling networks play an important role in providing advanced switching services. With the increase in the degree of the reliability of such switching services on common channel signaling networks, the common channel signaling networks are easily congested, and controlling congestion on these networks has become increasingly important. On the other hand, the network scale has been increasing with the development of the information society. With the increase in the network scale, signal transmission delay and control signal delay have increased, giving adverse effects on congestion control. In this article, the congestion control on common channel signaling networks recommended by CCITT has been analyzed considering the above‐said transmission delay and control signal delay. As a result of this analysis, the above‐said adverse effects could be evaluated quantitatively. A rigorous solution of this model could not be obtained. Thus, a method of analysis by fluid approximation is proposed. In addition, this approximating analytical method is shown to have sufficient practical accuracy in comparison with simulation results. By this analytical method, the rates of blocking of congested resources (signal links, circuits), mean delays, etc., can be easily obtained. As a result of the analysis, it is shown that these delays greatly influence the efficiency of congestion control. Especially, it is shown that the call loss rate shows a great effect; and control parameters must be determined considering these delays in order to satisfy certain standard values by congestion cont

ISSN:8756-6621    

DOI:10.1002/ecja.4410760105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe land mobile communication is affected by fading when the mobile station moves in the multipath transmission environment. On the other hand, there are cases where there is no fading as in the communication with the standing or transported mobile station. It has been understood that the coherent detection using PLL is better in the nonfading environment and the differential detection is better in the fading environment.From such a viewpoint, this paper proposes a detector diversity system for mobile communication which can cope with the complicated states of the transmission path by switching between the coherent detection (PLL) and the differential detection using the error‐detection code. The proposed system uses a simple error‐detection code, and the two detectors are switched by selecting the detector with a fewer number of detected errors. The feature of the system is that it is simple, being constructed by the existing PLL and the differential detector. The effectiveness of the proposed system is verified by computer simulat

ISSN:8756-6621    

DOI:10.1002/ecja.4410760106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractAn analysis method using Pocklington's integral equation is presented for wire antennas with lumped inductive loading along its arm. In the formulation of the integral equation, using the equivalence principle, the equivalent electric and magnetic currents on the coil surface are expressed instead of the current flowing on the coil and the electric field. The boundary condition that the axial component of the total electric field vanishes is applied on the antenna axis including the coil. Piecewise‐sinusoidal functions are used for the current expansion functions and the weighting functions.The numerical calculation is made for the different numbers of turns, pitch, and radius of the coil loaded at the midpoint or the top of a dipole antenna. The good agreement between calculated and measured values for the current distribution and input impedance are obtained. The analysis method proposed in this paper is applicable to antennas with resistive or capacitive loading by changing the expressions for the equivalent currents on the surface of load

ISSN:8756-6621    

DOI:10.1002/ecja.4410760107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper proposes an interference cancellation method called the in‐band power minimizing method (IPMM), and describes the use of the method in satellite communication earth stations. In this method, an interfering signal arriving from an earth station antenna is combined by a cancellation circuit with an interfering signal received by an auxiliary antenna and the two interfering signals are arranged to have equal amplitudes but opposite phase. To achieve this condition, the amplitude and phase are adjusted so that the signal power of the output signal from the cancellation circuit contained in the desired signal frequency band is to be a minimum. This method is characterized by the fact that a simple circuit can be used to detect interference rapidly and accurately even at lowC/Nratios.This paper also discusses the principle of IPMM and examines the results obtained when it is applied to small earth stations. It was found that IPMM is quite effective in this applicatio

ISSN:8756-6621    

DOI:10.1002/ecja.4410760108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe distribution of the positioning error in a global positioning system (GPS) depends on the allocation of satellites. Thus, the agreement between the covariance ellipse derived from the allocation of satellites and that derived from the positioning error distribution of the actually measured data is examined for two reception systems, i.e., the sequential and the parallel processing systems. The result shows that the two covariance ellipses agree well, although the situation depends a little on the shape of the ellipse as well as the azimuth and elevation of the satellite.The size of the ellipse is approximately one‐half in the parallel processing system compared to that of the sequential one. It is proved by the results of the analysis that the distribution of the error is anticipated before the measurement or the positioning during navigation and is represented by an ellipse. The method is applied to a navigating ship. It is shown that the display of the error distribution together with the positioned point is useful to the navigator in determining the steering of the ship in the sense that the reliability for the position of the ship is increase

ISSN:8756-6621    

DOI:10.1002/ecja.4410760109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA case exists in which cancellation of interference is not possible with an interference canceler which cancels the interference wave from ground radio stations mixing into the ground station for the satellite communication. It is found experimentally that this is caused by the difference in the frequency characteristics of the input signals to the two antennas by the multipath effects.Further, a method is proposed to discriminate whether the arriving interferences can be cancelled. Its effectiveness is confirmed experimentally. Whether or not the interferences can be cancelled can be determined by the amount of variation of the received electric field intensity of the interferences. If there is a signal with a constant‐shaped spectrum, the distortion of the shape can be used for discrimination. As a result, the condition and limit of applications of the interference canceler are foun

ISSN:8756-6621    

DOI:10.1002/ecja.4410760110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY