Multiplex communications – Pathfinding or routing – Combined circuit switching and packet switching
Reexamination Certificate
1997-10-16
2003-05-06
Vanderpuye, Ken (Department: 2661)
Multiplex communications
Pathfinding or routing
Combined circuit switching and packet switching
C370S353000
Reexamination Certificate
active
06560219
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a hybrid exchange for exchanging the STM (Synchronous Transfer Mode) data of narrow band calls such as voice data and the ATM (Asynchronous Transfer Mode) data of broad band calls and, more specifically to a hybrid exchange for exchanging the STM data in unit of each STM data by periodically transmitting this data using the STM time slot, an exchange for exchanging a plurality of STM data composite in unit of each STM data by periodically transmitting the data using the STM time slot and a re-arrangement method for STM data in exchange for re-arranging the STM data among a plurality of fixed length packets.
2. Description of the Related Art
FIG. 1
is a diagram showing an STM exchange for exchanging the STM data such as voice data. In the bTM exchange, the STM data which is periodically assigned to the time slot appearing on the frame in the predetermined period is exchanged in every time slot depending on the preset information For example, in
FIG. 1
, for the input line
1
, A is assigned periodically to the time slot TS
1
, while B to the time slot TS
2
and C to the time slot TS
3
. In the same manner, a, b, c are respectively assigned to each time slot in regard to the input line
2
. Depending on the preset information, the STM data A assigned to the time slot TS
1
on the input line
1
, for example, is exchanged to the time slot TS
2
of the output line
2
. As explained above, the exchange system in the STM exchange is suitable for the communication for periodically sending information such as voice data.
However, on the occasion of dealing with the communication for sending the information generated like a burst signal with the STM exchange, an idle area is generated in the time slot to be periodically assigned and thereby transmission efficiency may be deteriorated.
Therefore, for the data which is generated like a burst signal in the data terminal, etc., a packet exchange system has been proposed to realize exchange of data by using a packet of the variable lengths and then adding a header indicating the destination address to the packet. However, the packet exchange requires the time for exchanging one packet because it executes the exchange process by analyzing destination address of the header added to the packet. Accordingly, the packet exchange is not suitable for transmission of broad band data.
Considering the background as explained above, there is provided an ATM exchange system in which data is divided in unit of data of the fixed length; a header information is added to the divided data to generate ATM cells; these ATM cells are asynchronously transmitted and the ATM exchange executes the exchange process from the point of view of hardware depending on the value of header added to the ATM cell. According to the ATM exchange system, the data which is generated like a broad band burst signal may be transmitted as in the case of the dynamic image communication terminal.
FIG. 2
is a diagram showing a network in which the ATM exchange and STM exchange are used simultaneously. In
FIG. 2
, the ATM network
10
is composed of a plurality of ATM exchanges and transmits the data through the ATM cell which is the packet in the fixed length of 53 bytes. The ATM network
10
accommodates, on the one hand, ATM terminals X, Y for transmitting the ATM data and on the other hand, accommodates, STM exchanges
20
,
30
, via ATM interfaces
40
,
50
, to accommodate STM terminals a, b for transmitting the STM data.
The ATM data from the ATM terminal X is transmitted, for every generation of data, to the ATM network
10
through the payload of the ATM cell having the header H indicating the ATM terminal Y. The ATM network
10
transmits this ATM cell to the ATM terminal Y depending on the routing information of the header H.
Meanwhile, the STM data from the STM terminal a is superimposed on the time slots which are periodically assigned and then transmitted to the STM exchange
20
. For example, when the STM terminal a is designed as a voice terminal of 64 Kbps, the STM data is transmitted through the time slot of 8 bits assigned in the period of 125 &mgr;s. This STM data is processed first in the STM exchange and then transmitted to the ATM interface
40
. The ATM interface is provided for transferring the data between the time slot and ATM cell with each other. The ATM interface
40
loads this ATM data, for transmission to the ATM network
10
, to one byte of the payload of the ATM cell having the header directed to the STM exchange
30
accommodating the STM terminal b. The ATM network
10
transmits the ATM cell loading this STM data, without any discrimination from the ordinary ATM cell, depending on the routing information of the header H of the ATM cell. The ATM interface
50
extracts, upon reception of this ATM cell, the STM data from the predetermined position of the payload and then sends this ATM cell to the STM exchange
30
using the time slot periodically assigned. The STM exchange
30
executes the exchange process of the time slot and then sends the STM data to the STM terminal b of the destination address.
In the present situation, the greater part of the terminals is formed almost of the STM terminals such as telephone sets and ATM terminals are only introduced gradually by means of dynamic image communication terminals. Therefore, it will be very convenient when the ATM terminals which are gradually introduced can also be accommodated in the STM exchange as well as the STM terminals.
However, the STM exchange intrinsically introduces the synchronous transfer mode system for periodically assigning the time slot in unit of STM data to each STM terminal. For example, the telephone set of 64 Kbps is manufactured based on the hardware and software for exchanging and processing the data by assigning the time slot in unit of 8 bits for every other 125 &mgr;s. Therefore, the STM exchange of the related art has a problem that it cannot execute the exchange process for the ATM cell in unit of 53 bytes in different exchange unit.
Meanwhile, the ATM exchange is designed on the basis of the hardware and software of the asynchronous transfer mode for transferring the data as required when data is generated as the ATM cell of 53 bytes. Accordingly, when it is required to manufacture the STM exchange and ATM exchange, it is impossible to use in common the hardware and software for the STM exchange and ATM exchange and thereby there rises a problem that manufacturing cost cannot be reduced.
SUMMARY OF THE INVENTION
It is an object of the present invention to reduce manufacturing cost and effectively develop the STM exchange and the ATM exchange by using common hardware and software for the basic configuration of the STM exchange and the ATM exchange.
It is another object of the present invention to provide a hybrid exchange for exchanging the STM data to be transmitted periodically to enable the data exchange in unit of the ATM data to be transmitted asynchronously.
Yet another object of the present invention is to provide a hybrid exchange for enabling transmission of STM data such as voice data through reduction of the transmission delay.
A further object of the present invention is to provide a hybrid exchange which is connected to an ATM exchange for transmitting the ATM data in the form of ATM cell in order to transmit and exchange the STM data of the STM time slot even with an ATM exchange.
Yet another object of the present invention is to provide an exchange which establishes reception sequence of the STM data for communication of the STM data via the ATM network including the ATM exchange.
Yet a further object of the present invention is to provide an exchange which enables efficient use of payload for transmission of a plurality of STM data in the form of the ATM cell of the payload composite.
These and other objects of the invention are attained by a hybrid exchange for exchanging periodically transmitted first data and second data through time-division slots
Inoue Sachiko
Kubota Yoshihiro
Murayama Masami
Suzuki Hidehiko
Tabu Takashi
Katten Muchin Zavis Roseman
Vanderpuye Ken
LandOfFree
Hybrid exchange, an exchange, and a re-arrangement method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hybrid exchange, an exchange, and a re-arrangement method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hybrid exchange, an exchange, and a re-arrangement method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3054286