WO2001093449A1

WO2001093449A1 - Plc system

Info

Publication number: WO2001093449A1
Application number: PCT/DE2001/001977
Authority: WO
Inventors: Werner Troks
Original assignee: Siemens Aktiengesellschaft
Priority date: 2000-05-30
Filing date: 2001-05-23
Publication date: 2001-12-06
Also published as: DE10026928A1

Abstract

The invention relates to a PLC system, which comprises the following elements in order to prevent malfunctions during the data exchange of users, while maintaining a high transmission capacity: in addition to the working channels, </= chimnies >/= , which are responsible for the data exchange between users wishing to communicate, a communications channel (broadcasting channel) that has been set up specifically, which provides general access for the users wishing to communicate and which at least substantially serves the purpose of establishing and/or clearing a connection between the users wishing to communicate and of synchronizing said users with one another.

Description

description

PLC system

The invention relates to a PLC system according to the preamble of claim 1.

It is known to process data exchange processes between participants involved in the data exchange processes using suitable means via the electrical power supply network of the participants affected by the data exchange processes. The term "Powerline Communication" (PLC) was coined for this data exchange technology.

Powerline communication is used in particular by power grid operators to control services or read meters. However, large amounts of data cannot be processed for these services or applications.

In recent times, as technology advances, attempts have been made to use the energy supply network transmission medium for the transmission of larger amounts of data during data exchange processes. The user data are modulated onto appropriate carriers by various methods and sent via the energy supply network.

In Europe there is a leading committee called CENELEC (Co ite Europeen de Normalization Electrotechnique), which has approved a frequency band from 3 kHz to 148.5 kHz for the PLC, within this frequency band again specifying bands A to D for different services has been made. The frequencies and transmission levels are specified in a standard EN 50065 (signal transmission on electrical low-voltage networks in the frequency range 3 kHz to 148.5 kHz). There is something similar in the United States and Japan. However, a frequency range up to approx. 500 kHz has been released in these countries.

The energy supply network as a transmission medium is very susceptible to faults. Elaborate techniques have to be used to enable perfect communication between the participants in data exchange processes. However, new technologies in the CENELEC band in Europe only create a maximum of 155 kbps (kilobits per second). For this reason, attempts are currently being made to transmit the user data in a larger frequency range (up to 30 MHz). However, this change still has to be approved by the regulatory authorities.

The power grid operators in particular are very interested in bridging the so-called "last mile" and also offering Internet from the socket. The "last mile" is the route from a last high-voltage transformer to a consumer, who, however, need not be an individual consumer. For example, such a consumer is also to be understood as a larger group of individual consumers, such as that provided by companies or combined house units. The area of the "last mile" is also referred to as the so-called access or outdoor area. This contrasts with the so-called in-house or indoor area, which is the area within a consumer defined above.

In the in-house area, data networks for so-called SOHO areas can be set up using the PLC. In a figurative sense, SOHO areas are island areas that are optimized for the transmission of special data. Areas that specialize in video and / or telephony and / or data and / or telemetry transmissions can be mentioned here as examples. Each area must meet its own performance criteria. Each of these areas therefore forms its own transmission system. Further must not only between the individual _Ü bertragungssystemen be differentiated but also between the house and the outdoor area per se, which are assigned to ver ^¬ different frequencies.

The PLC has the advantage that no new lines have to be laid and that compared to radio solutions, higher data rates can be achieved during transmission.

It is problematic, however, that when operating and interacting different and / or the same transmission systems or the in-house and outdoor areas, there are no disruptions within the individual systems or areas.

To avoid such interference, the so-called "chimney approach" has been proposed by the specialist for the amateur radio bands and radio transmitters, according to which interference-free transmission is possible in different bands ("chimnies"). With the Chimney Approach, an overall possible transmission frequency bandwidth is divided into smaller frequency band ranges. Participants willing to communicate accomplish their data exchange in an agreed frequency band range of these smaller frequency band ranges and in this way disturb non-communicating participants who accomplish their data exchange in another of these smaller frequency band ranges. Individual ones of the smaller frequency band ranges can be used alone or together with other smaller frequency band ranges predominantly or mainly for certain transmission systems. On which or which actual frequency band areas a data exchange takes place between participants willing to communicate, at the beginning of a data exchange process, as already mentioned above, must be agreed in advance by the participants involved in the data exchange.

In order for an advance agreement to be reached, the partners must first of all make contact in The processes for the first-time contact of participants in a communication are extensive and are currently taking place in parallel with the processes of existing connections in the same frequency band range in which the respective connections exist. The existing and also the new connections can therefore interfere with each other.

The more extensive the processes for establishing a connection, the greater the risk of mutual interference. If participants wishing to communicate first have to synchronize with each other, the potential for interference is particularly high. Clearing a connection also contributes to the potential for interference. The potential for interference reduces the performance of the PLC system.

The object of the present invention is to provide a PLC system of the type mentioned at the outset in which the potential for interference is reduced and thus the performance of the PLC system is increased.

This object is achieved with the characterizing features of claim 1.

Through the introduction of a broadcast channel, through which the administrative processes necessary for a data exchange connection are dealt with, i.e. independent of the processes of pure data exchange on other channels (working channels; "Chimnies"), those processes that are necessary so that there are two Can communicate participants, the work channels are spared further burdens and the potential for interference between the participants willing to communicate is reduced. The individual channels can also be optimized individually. Overall, the PLC system is highly efficient. A further advantage is that with the introduction of the broadcast channel to each system can synchronize to an existing Sy ^¬ stem, so that a combination of all PLC systems possible. It is therefore possible to divide it into classes (e.g. video, audio, in-house, outdoor, telephony, telemetry, etc.). After synchronization, you can switch to the system, frequency or modulation type determined before the actual data exchange. A complex data backup is only necessary after switching to a transmission channel.

Everyone e.g. So-called client (participant), which is switched on, checks whether there is broadcasting on the broadcast channel. If there is no transmission on the broadcast channel, a send request can be sent. For example, if there is no response within an agreed time, neither a so-called master (participant) nor a client (participant) is in use. The requesting participant can then register as a master (participant). If an answer is given, the participants must agree on a protocol mechanism, a frequency, a master / client assignment, etc. You can then continue working with the agreed protocol mechanisms in secure mode, for example.

Advantageous embodiments of the invention are the subject of dependent claims.

The broadcast channel is then installed in such a frequency band range in which protocol mechanisms are already used. These protocol mechanisms can then be used and it is not necessary to introduce new protocol mechanisms.

In detail, the CENELEC C or D band can be used for such a broadcast channel, for example, because this frequency band meets the specified criteria. Other frequency bands can also be used. An exemplary embodiment of the invention is explained in more detail below with reference to a drawing.

In the drawing, the only figure shows a block diagram which is an example of the principle of the registration of a participant willing to communicate via a broadcast channel.

Registration begins with a first time period 1. In a subsequent second time period 2, a check is carried out to determine whether the broadcast channel is busy, i.e. whether the broadcast channel is being used.

In a third time period, a decision is made as to whether the broadcast channel is occupied or not. If the broadcast channel is busy, the notification process is restarted with the measures from the first time period 1. If the broadcast channel is free, the request for registration is sent to the broadcast channel in a fourth time segment 4.

In a fifth time period 5, it is waited whether a desired partner answers on the broadcast channel. If a response is not sent within a specified period of time, the registration process is either canceled completely, at a later time or immediately started again to repeat the registration.

If a response is received within the specified period of time, a mutual exchange of the respective authorizations takes place in a sixth time segment 6 and then a change from the broadcast channel to a mutually agreed-upon working channel ("chimney") for a data exchange to be carried out.

Claims

claim

1. PLC system with features according to the "Chimney Approach", characterized in that at least one generally accessible for communication-willing participants of the PLC system, at least essentially communication purposes for establishing a connection and / or disconnection between communication-willing participants and for the synchronization of A communication channel serving one another (broadcast channel) is provided in addition to the working channels (“chimnies”) responsible for data exchange between the participants willing to communicate.

2. PLC system according to claim 1, characterized in that the communication channel is installed in an already existing frequency band area with already existing protocol mechanisms.

3. PLC system according to claim 2, characterized in that the communication channel is installed in the CENELEC band.