Aleksandr Zhoga

Аleksandr Zhoga

ABSTRACT

of Master’s qualification thesis on

“Research and development of the combined system of transmitting telegraphic messages in general use networks” 

 Introduction

With the advent of telephone connection, telegraph had to make room; however, it still has irrefutable advantages. Telegraphic services are still popular among both private and legal persons. These include banks, insurance companies, governmental institutions and organs of all levels – from regional administrations and courts to ministries and presidential administration. Telegrams may contain diverse information, any message requiring documental confirmation of being sent and received, which may be further used in legal cases. Advantages of telegrams are not restricted to their “judicial power”. For official messages they mean the fastest and guaranteed way of delivery with various means of sending.

Relevance of the subject

With messages interchange sooner or later there arises a problem of transmitting information to different networks, e.g. between Internet and Telex networks users or between facsimile and telegraphic networks. Also each Internet user encounters a problem of guaranteed delivery of the message to recipient’s mailbox and read message receipt. However, there’s a possibility to send messages by means of special electronic mail which is capable to send an electronic message not only to e-mail address but simultaneously to fax, telex and to postal address where it would be delivered in the form of telegram or paper letter, send a message in the form of SMS to mobile phone subscriber, receive and read a telegram, fax, voice or SMS message. But for all that codes converting problems may arise as users may use different mail clients. Therefore, research of the message conversion algorithm will help solve the problems arising at message transmitting to different networks.
The concept of the system is realization of the Unified Messaging, integrating existing technologies of data transmitting and up-to-date, perspective telecommunication services:

• electronic mail,
• voice mail,
• fax,
• telex,
• telegram,
• SMS,
• hybrid mail and other.

Relation to scientific programs, plans, subjects

This qualification Master’s thesis has been written within 2009-2010 in accordance with scientific direction of the Automation and Telecommunication Chair of the Donetsk National Technical University.

 Aim and objectives of the research

The aim of research and development of the combined system is organization of various type messaging (fax, telex, e-mails containing text and any files, typical postal messages) between subscribers with different equipment, which would allow for integration of all possible data processing technologies on one working place (telegraphic terminal, postal client, Internet access).
This aim is supposed to be achieved through accomplishing the following objectives:
- message re-coding methods analysis;
- recommendations on creating a message processing algorithm;
- program realization of the proposed processing algorithm.

Prospective scientific novelty

This work is not absolutely new in its subject area as these problems are dealt with by a number of Russian companies. On the territory of Ukraine there are no analogues, therefore, the proposed idea will allow to gradually or at once replace the outdated equipment (AT stations/TELEX) with modern means of data processing and to widen the range of documental network services.

 Practical meaning of the results achieved

Practical meaning of the research is defined by the fact that the proposed system will enable its subscribers to interchange messages of different types using various technical means and connection channels for this aim.
Nowadays successful operation of any financial structure is conditioned by effective unified information system constructed with the use of advanced telecommunication technologies and meeting international standards. Let us help them cut expenses on messaging.
This will also enable Internet-providers and other networks operators striving to gain a competitive advantage and increase number of clients, to widen their services with the new group of connection services – documental means of communication (telex, fax, SMS, postcard and letter, telegram, voice and hybrid mail).

 Overview of researches and development of the subject

REX400 is one of the similar developments. REX400 is a domestic system, developed by CJSV Club 400 in compliance with international standards for open systems Х.400, which supports the majority of standard data transmitting protocols (Х.25, TCP/IP, Х.28, Х.400, UUCP and other), which provide for compatibility with the majority of modern systems, above all Х.400 and Internet.
This is a complete technical solution for organization of reliable corporative systems of different type data interchange and multifunctional systems for network operators.  The system is most convenient for companies and organizations with widespread infrastructure of geographically remote locations of presence, where the communication system is needed for providing efficient and reliable electronic data interchange.
Such important tasks of electronic interchange for various organizations and companies may include: exchange of monitoring data, reports, statistics, directives, applications.
As an example of the work we may take the use of the system for organization of transport medium on the “client-bank” system, where client of the bank interacts with the bank system via specialized applied “client-bank” program. Upon completion of data formation on the client’s side the Autonomous Transporting Module REX400 takes up the data and transmits it within an e-mail message to the mail box of the recipient with whom the bank system interacts using the same Autonomous Transporting Module REX400.
Playing the role of the guaranteed transactions medium, the system in this mode may be applied for making transactions in payment systems with payment reception points in different geographical locations; for providing transactions interchange between remote client’s places and centralized database etc. This organization offers a wide range of services. [1] But it is not the only one on the market of telecommunication services – there’s a similar company CBOSS.
It provides services of the all-round automation of communication business. Among various IT-solutions of this company the most interesting is the transformation gateway of SMS messages to facsimile. [2]
The aim of this work is to research message processing algorithms offered by various companies. The main difficulty of the analysis is the fact that such information is closed, therefore, the research is based on the analysis of open out coming codes of similar systems.

Problem statement

 The analysis will be conducted on the basis of REX400 system. Unlike foreign functional analogues, system REX400 allows to combine various telematic services, networks and systems including fax, telex, telegraph, electronic mail X.400 and other on one computer. The system uses Х.400 data transmitting protocol which is almost devoid of problems peculiar to other technologies (unprotected access to subscribers’ information, unreliable messaging, re-coding of transmitted information and other). REX400 guarantees not only the fact of delivery but also a definite time of message transmitting.
Х.400-based systems are used where requirements to authenticity, reliability and security of information are high – in banking structures, corporative networks, governmental institutions (customs, tax authority, treasury etc.). Electronic post-office based on Х.400 is adapted for large territorially distributed organizations as it provides for flexible routing, reliable, efficient and safe delivery of messages of all type (text and facsimile, graphics and voice, telegrams and telexes) as well as administrating and receiving complete statistics of postal network exchange.
Let us consider possibility of sending an electronic message in form of telegram and SMS and vice versa.

Figure 1 - The principle of the combined system of communication
(animation: volume- 50,8 KB; size - 400х429; delay between the last and first shots - 3000 ms; number of repetion cycles - continuously)

E-mail

There are many computer networks which are not part of Internet but currently connected via gateways allowing for e-mail transfer.
When using e-mail one should realize that despite its efficiency it is not a telephone but postal connection. All messages are written, thus, almost documented, therefore, one should follow the etiquette of normal correspondence. In addition, e-mail doesn’t have the same privacy level as normal post, thus, if no additional encryption methods are used, nothing confidential should be written in an e-mail. Anonymity is also out of question – the source may be easily traced back.
In order to make the message delivered to its addressee it is necessary to formalize it in compliance with international standards and send form standardized electronic address. The common message format is defined by the document titled "Standard for the  Format  of  ARPA- Internet Text messages", in short Request  for  Comment  or  RFC822 and has a title and a message itself.
The title looks like this: 

    - From: postal electronic address – sender of the message

    - To: postal electronic address - addressee

    - Cc: postal electronic address – other addressees

    - Subject: subject of the message (free form)

    - Date: date and time of sending the message

The title lines From:  and  Date: are, as a rule, formed automatically by program means. Beside these lines the message may contain other lines, for example:   

     - Message-Id: unique message identificator, attributed by mail machine

    - Reply-To: usually, subscriber’s address to which the reply is sent

Let us consider an example of a postal message:

Received: by avg386.kiae.su; Thu, 20 Dec 90 13:51:59 MSK

Received: by jumbo.kiae.su; Thu, 20 Dec 90 12:52:17 MSK

Received: from CS.ORST.EDU by fuug.fi with SMTP id AA15539 (5.65+/IDA-1.3.5

         for avg@kiae.su); Thu, 20 Dec 90 08:19:05 +0200

Received: from jacobs.CS.ORST.EDU by CS.ORST.EDU (5.59/1.15) id AA19981;

         Wed, 19 Dec 90 22:19:59 PST

Received: by jacobs.CS.ORST.EDU (5.54/1.14) id AA02240; Wed, 19 Dec 90

         23:19:35 MST

Date: Wed, 19 Dec 90 23:19:35 MST

From: Harry Brooks

Message-Id: <9012200619.AA02240@jacobs.CS.ORST.EDU>

To: avg@kiae.su

Subject: Re: wondering if you attended?

Status: RO

"Text of the message"

The massage consists of a text, which has to be transmitted to the recipient, and a title, which is stated at the beginning of the message and separated from the text by an empty line and contains several lines about this message: date of sending, address, return address, subject and other.
Here the first fourteen lines comprise title. Let us note that each of the lines has the following form:

title: text

    - subscriber’s identificator (analogous to the line  TO: on the envelope);

    - postal coordinates which define its location (analogous to building, street, city, country on the envelope).

Postal electronic address has all these components. In order to separate subscriber’s identificator from his postal coordinates, a @ symbol is used. @ is a separator which is also referred to as “at”.
Electronic address in Internet format has the following form:

                     User_name@name_computer

When non-text data are transferred (program, graphics) the re-coding of messages is made by respective program means. [3]

Telegram 

Telegraphic connection, long distance transmission of the messages – telegrams – conveyed by electrical signals transmitted through wires or radio waves. Any text containing letters and digits is discreet: irrespective of its content it may be expressed by a final, comparatively short set of characters – letters, digits, punctuation marks. Therefore, the telegraphic connection system components, namely telegraphic devices, designed for transmitting a definite, pre-defined number of different elementary signal combinations.
To each such combination, called code combination, corresponds a letter or digit. Telegraphic connection uses binary signals, i.e. signals that may possess one of the two possible values. This provides for maximum protection of signals from line or channel noise and simple message transmitting devices.Transmitting of code combinations may be carried out by binary signals of various types. Picture 1 shows the most common binary signals form.  

Figure 2 – Types of binary telegraphic signals: a – single-pole signals of direct current; b – double-pole signals of direct current; c - frequency-modulated signals of alternating current; u – voltage; t- time; f1 and f2 – frequency values of alternating current binary signals.

Direct current signals (single- and double-poled) are used at message transmitting to comparatively short distances (usually, not exceeding 300-400 km) by cable and air lines (physical chains). On main lines transmitting is carried out by frequency-modulated double-pole signals of alternating current, using telephone channels as lines. This enables receiving up to 44 independent channels in one telephone channel. Tonal telegraphing equipment is used with this aim. Technical characteristics include: telegraphy speed, reliability, breakdowns rate. Telegraphy speed (transmittance speed) is measured in quantity of elementary signals transmitted per second.

          Table 1 - Speed transfer

Number of symbol transmitted in a minute is calculated by formula:

                                                                                                                                                                     (1)

where V — transmittance speed in bod; n —  number of elementary signals per one symbol. Number of words transmitted in an hour is calculated by formula:

                                                                                                                                                   (2)

Values V, W and QT for transmitting by telegraphic code № 2. In this code combinations of current pulse differ only by sequence of positive and negative pulse. For even codes to which code # 2 belongs, the number of possible combinations N is determined by a formula: N=m*n, where m is an amount of code elements, n is founding of code. QЭ operating norm is also indicated there, which differs from theoretical QT by the amount of time spent by operator on implementation of second-rate functions at a transmission and receipt of telegrams. Correctness of transmission is a relation of amount of symbols, received with errors (for the correctness measurement session), to the general amount of symbols transmitted. This amount is also referred to as the errors coefficient. According to the International Consultative Committee for Telegraphy and Telephony (CCITT) recommended norm of errors coefficient amounts to on average no more than three errors on 100 000 symbols transmitted. The failure coefficient shows, how often an operator establishing a connection within a gated network for telegram transmission, gets a "busy" signal. This signal appears when the called station or interconnect devices on intermediate telegraph knots is busy. The failure coefficient is rationed for the period (hour) of the most loading and expressed as a percentage ratio of connection failures to the general amount of calls. The norm on the failure coefficient is 17% for connection through 6 intermediate knots. [4]

SMS

SMS stands for Short Message Service. This is a technology which allows sending and receiving messages by means of mobile telephones. SMS first appeared in Europe in 1992. It was included into the GSM (Global System for Mobile Communication) standard from the very beginning. Later it was exported to wireless technologies such as CDMA and TDMA. GSM and SMS standards were initially developed by ETSI. ETSI is an abbreviation of European Telecommunications Standards Institute. Now 3GPP (Third Generation Partnership Project) is responsible for development and servicing of GSM and SMS standards. SMS messages are rather limited. One SMS message may contain no more than 140 bites (1120 bits) of data, therefore, one SMS may contain up to:

- 160 symbols, with the 7-bit encoding (the 7-bit encoding is suitable for encoding of the Latin alphabets, such as English alphabets);

Conclusion

Bibliography

10. Курс «Технологии Интернет». [Electronic Resource] – Mode of access: http://athena.vvsu.ru/

11. Коханович Г.Ф., Чуприн В.М. Сети передачи пакетных данных . [Text]. — К.:"МК-Пресс", 2006. — 272 с.

At the moment this abstract writing the Master’s thesis is not complete. Date of completion is December 1, 2010. Unabridged text of the work and thematic materials may be obtained from the author or his supervisor after the stated date.