The structure and modeling results of the parallel spatial switching system

The structure and mo deling results of the parallel spatial switc hing system Denis Kutuzo v ( d_kutuzov@mail.ru ), Alexey Osovsky April 20, 2007 Information Systems Dept., Astrakhan State Univ ersity , 20a, T atischev a Str., Astrakhan, 414056, Russia, ( http://www.aspu.ru/ ) Abstract Problems of the switching parallel system designing provided spatial switc hing of pac k ets from random time are discussed. Results of modeling of switc hing system as systems of mass service are resulted. Index T erms: parallel switching, information systems, system of mass service, pack et switching, communication net work. The increase of rate of switching system elements, as w ell as other devices o ccurs basically due to adv an tages in technological base. A t the same time an- other decision is possible. It is perfection of algorithms and methods of switc hing and creation a new switc hing decisions, not dep enden t on technological base. Suc h decision for switching systems may become a parallel pro cess metho d whic h w ould allo w to increase transfer rate and to decrease losses at pro cessing pac kets. The parallel switc hing system [ 1 ] pro vides a parallel spatial switching of the information pac kets at the random moments of time and consists of the follo wing blo c ks (see Fig. 1 ): blo c k of synchronization of the input pack et with the momen t of iden tification (1), elemen ts of switc hing (2) and blo c ks of tag generation for the target lines (3). Op eration of system is carried out with the following algorithm: a require- men t of connection establishment is transferred on the system input. Eac h requiremen t represen ts the information pac ket ha ving headline (tag) which iden- tifies a target line of the switc hing system whic h it is necessary to send the giv en pac ket. As requirements of the establishment connections (pack ets) arriv ed on the system inputs at the random time, that is asynchronously , and identifica- tion v is p ossible only at the certain moments of time, the requirement (pack et) should b e delay ed up to the momen t when the tag comparison and to start switc hing is p ossible. Suc h delay is carried out by blo c ks of pack et synchroniza- tion with the momen t of iden tification and ma y b e v arious for the pac k ets which ha ve arrived at die different time. Some requirements (pack ets), exp ecting the b eginning of identification represent a pack. 1 Figure 1: The structure of the parallel spatial switching system Iden tification represen ts pro cess of bit-b y-bit tag comparison for connection lines (it con tains in a pack et), and the target line tags whic h generated blo c ks 3 (Fig. 1 ). At coincidence of the target line tag with heading tag in the pack et, the appropriate switc hing elemen t establishes connection for transfer of pack et on the system output. After transfer of the pack et the connection should b e destro yed. All functions of the conflict resolution, for example, at attempt of t wo and more input lines to establish connection with one target line are assigned to switc hing elements 2 (Fig. 1 ). Diagrams of loss probabilities of pack ets (P) from av erage (mo deling) time b et w een pack et receiving are sho wn in Fig. 2 . Figure 2: The mo deling results of the parallel spatial switc hing system It is p ossible to make a conclusion on reduction of loss probability in com- 2 parison with the system with consecutive switc hing b y results of mo deling of the parallel switching system [ 2 ]. The diagram 1 in Fig. 2 corresp onds to parallel switc hing system, the diagram 2 is consecutive one. References [1] D.V. Kutuzo v, “P arallel adjustment of matrix switching system at dynami- cal requirements” // Engineering and technology , 2005. No. 2(8), pp. 57–59. [2] A.P . Lunev, I.Y u. Petro v a, D.V. Kutuzov, A.V. Oso vsky , “Simulation of matrix switch b oards”. The patent regisrtation No. 2005611003, the legal o wner Astrakhan State Universit y . 3