阅读说明：本技术 飞行器通信系统的交换机和相关联的飞行器通信系统及传输方法 (Switch for an aircraft communication system, and associated aircraft communication system and transmission method ) 是由 阿兰·迪加 阿诺·西特邦 邦雅曼·弗拉芒 埃里克·菲特雷 于 2021-06-29 设计创作，主要内容包括：本发明提供一种飞行器通信系统的交换机和相关联的飞行器通信系统及传输方法。本发明进一步提供一种用于传输帧的形式的数字数据的交换机(22A),每一帧具有识别字段,并且是符合ARINC 664 P7类型的协议的第一类型或符合IEEE 802类型的协议的第二类型。交换机(22A)包括多个输入端口(31)、多个输出端口(32)和配置表(33),对于每个识别值,配置表(33)包括具有该识别值的帧的传输参数。交换机(22A)能够仅基于配置表(33)中与每一帧的识别值相对应的传输参数,在输入端口(31)与至少一个输出端口(32)之间切换该帧,而与该帧的类型无关。(The invention provides a switch of an aircraft communication system, an associated aircraft communication system and a transmission method. The invention further provides a switch (22A) for transmitting digital data in the form of frames, each frame having an identification field and being of a first type conforming to a protocol of the ARINC 664P7 type or of a second type conforming to a protocol of the IEEE 802 type. The switch (22A) comprises a plurality of input ports (31), a plurality of output ports (32) and a configuration table (33), the configuration table (33) comprising, for each identification value, the transmission parameters of the frame having the identification value. The switch (22A) is capable of switching each frame between the input port (31) and the at least one output port (32) based on only the transmission parameter in the configuration table (33) corresponding to the identification value of the frame, regardless of the type of the frame.)

1. A switch (22A) for an aircraft communication system (20), the switch being capable of transmitting digital data in the form of frames, each frame having an identification field and being of a first type or a second type, the identification field of each frame defining an identification value, the frames of the first type conforming to an ARINC 664P7 type protocol and the frames of the second type conforming to an IEEE 802 type protocol, the set of frames of the first type having the same identification value forming a single stream of the first type and the set of frames of the second type having the same identification value forming a single stream of the second type;

the switch (22A) comprising a plurality of input ports (31) capable of receiving frames, a plurality of output ports (32) capable of transmitting frames received by one or more of the input ports (31), and a configuration table (33), the configuration table (33) comprising, for each identifying value, a transmission parameter for the frame having that identifying value;

the switch (22A) is capable of switching each frame between the input port (31) and the at least one output port (32) based only on the transmission parameter in the configuration table (33) corresponding to the identification value of the frame, regardless of the type of the frame.

2. The switch (22A) of claim 1 wherein the identification field of each frame corresponds to a MAC DEST field of the frame.

3. The switch (22A) of claim 1, wherein, for each identification value, the transmission parameters define a timing period of frames having the identification value and at least one output port (32) for the frames.

4. The switch (22A) of claim 3 wherein, for each identification value, the transmission parameter further defines at least one element selected from the group consisting of:

-dithering of the frames having the identification value;

-an input port (31) for a frame having the identification value;

-a priority of the frame having the identification value;

-the maximum size of the data packet transmitted by the frame having the identification value;

-a minimum size of a data packet transmitted by a frame having the identification value;

-an identifier of a set of output ports available for the frame having the identification value;

-the life cycle of the frame having the identification value.

5. The switch (22A) of claim 3, wherein a timing period defined by the transmission parameter for each identification value of a frame of the second type is equal to a predetermined value.

6. The switch (22A) of claim 1, wherein the set of identification values and corresponding transmission parameters for the first type of frame are determined statically in the configuration table (33).

7. The switch (22A) according to claim 1, wherein the set of identification values and/or the corresponding transmission parameters of the frames of the second type are determined statically or dynamically in the configuration table (33).

8. The switch (22A) according to claim 7, wherein the set of identification values and/or the corresponding transmission parameters of the frames of the second type are determined by self-learning.

9. The switch (22A) of claim 1, wherein the configuration table (33) is stored in a content addressable memory, each identification value representing an address in the addressable memory.

10. The switch (22A) of claim 1 configured to: applying at least one filtering operation to the input and/or output of each frame according to the transmission parameter corresponding to the identification value of the frame.

11. The switch (22A) of claim 1 configured to: each frame of the second type is transmitted using a best effort technique.

12. The switch (22A) of claim 1 wherein the processing parameter associated with each identification value has the same property regardless of the type of frame defining the identification value.

13. An aircraft communication system (20), comprising:

-a plurality of switches (22A, … …, 22N) connected to each other to form one or more computer networks, each switch (22A, … …, 22N) being in accordance with any preceding claim;

-a plurality of devices (24A, … …, 24M), each device (24A, … …, 24M) being a sender and/or a receiver of frames of the first type and/or the second type and being connected with at least one switch (22A, … …, 22N).

14. A transmission method implemented by the switch (22A) according to any one of claims 1 to 12, the transmission method comprising the steps of:

-receiving (110) a frame;

-determining (120) the identification value of the received frame;

-determining (130) the transmission parameter in the configuration table (33) corresponding to the identification value;

-exchanging (150) a received frame between the input port (31) and the at least one output port (32) only on the basis of the determined transmission parameters, irrespective of the type of the frame.

Technical Field

The invention relates to a switch for an aircraft communication system.

The invention also relates to an aircraft communication system and an associated communication method.

In particular, the invention enables a hybrid aircraft network to transmit frames conforming to a protocol of the ARINC 664P7 type and conforming to a protocol of the IEEE 802 type different from the ARINC 664P7 protocol.

Background

The ARINC 664 standard is known for implementing aircraft computer networks. It is derived from the ethernet standard, which in particular allows adaptation of the standard to the aircraft environment, in particular to aircraft limitations. It may be noted that the a664 standard is incompatible with the IEEE 802.3 ethernet standard due to its adaptability.

The ARINC 664 standard consists of several parts, for example: a portion dedicated to the system concept, a portion dedicated to the physical layer, and a portion dedicated to the services and protocols (IP).

Among these, in particular the Part known as "P7", which is commonly referred to as "ARINC 664P 7" or "ARINC 664Part 7" orAnd (4) showing.

This section P7 may be used to transfer aircraft data between different aircraft systems that perform the basic functions of the aircraft and therefore has the most constraints.

Thus, an aircraft network implemented according to section P7 may have an isolated, redundant, and deterministic network. The certainty of the network means in particular that each frame transmitted reaches its destination with the longest time known. In particular, isolated means that one or more users that do not comply with the time constraints of the a664P7 standard cannot disrupt the proper operation of the network.

In some aircraft networks, one or more protocols of the IEEE 802 family may also be used. As is well known, this family includes the ethernet 802.3 protocol or the WiFi IEEE 802.11 protocol.

The a664P7 standard was created to allow the use of data networks in critical environments. More specifically, it allows isolation of data streams with very small granularity, which is not possible with the IEEE 802 family of protocols.

In the aircraft world, the ethernet protocol may also be used to transfer data, which may be, for example, maintenance data, download data, passenger entertainment data and/or crew services functions related to different aircraft systems. In the event of loss of this data, it is therefore possible to retransmit this data without any risk to the safety of the aircraft.

Typically in aircraft, ARINC 664P7 and IEEE 802 networks are isolated from each other. This isolation is achieved by implementing these networks using different physical means.

In particular, this means that to ensure this isolation, these networks use physically different switches and transport means.

It is conceivable that this type of isolation would mean at least doubling each physical component to implement these networks. This means that there are many problems in terms of space, power consumption and weight in the structures (e.g. aircraft) hosting these networks.

In the prior art, some examples of so-called hybrid networks (i.e. ARINC 664P7 and IEEE 802 type networks) are already known.

Thus, for example, application FR1874166 by the applicant discloses a hybrid aircraft system implementing ARINC 664P7 and an ethernet protocol hybrid with predetermined routing.

In particular, such a system comprises a switch adapted to determine the protocol of each frame as it is received and to process the frame accordingly according to the determined protocol.

Although this system has significant advantages, it may still have disadvantages.

In particular, the operation of the switches in such systems is not always optimized, since specific processing of the frames of each protocol is required.

Disclosure of Invention

The object of the invention is to optimize the operation of the switches of a hybrid aircraft system.

To this end, the object of the invention is a switch for an aircraft communication system capable of transmitting digital data in the form of frames, each frame having an identification field and being of a first type or of a second type, the identification field of each frame defining an identification value, the frames of the first type being compliant with an ARINC 664P7 type protocol and the frames of the second type being compliant with an IEEE 802 type protocol, the set of frames of the first type having the same identification value forming a single stream of the first type and the set of frames of the second type having the same identification value forming a single stream of the second type;

the switch includes a plurality of input ports capable of receiving frames, a plurality of output ports capable of transmitting frames received by one or more of the input ports, and a configuration table including, for each identification value, a transmission parameter for frames having the identification value.

The switch is capable of switching each frame between the input port and the at least one output port based only on the transmission parameter in the configuration table corresponding to the identification value of the frame, regardless of the type of the frame.

According to other advantageous aspects of the invention, the switch comprises one or more of the following features considered alone or in any technically feasible combination:

-the identification field of each frame corresponds to the MAC DEST field of the frame.

-for each identification value, the transmission parameter defines the timing period of the frames having that identification value and at least one output port for the frames.

-for each identification value, the transmission parameter further defines at least one element selected from the group comprising:

-the jitter of the frame with the identification value.

-an input port for a frame having the identification value;

-a priority of the frame having the identification value;

-the maximum size of the data packet transmitted by the frame having the identification value;

-a minimum size of a data packet transmitted by a frame having the identification value;

-an identifier of a set of output ports available for the frame having the identification value;

-a life cycle of the frame having the identification value;

-the timing period defined by the transmission parameter for each identification value of the frames of the second type is equal to a predetermined value;

-statically determining in a configuration table a set of identification values and corresponding transmission parameters for frames of the first type;

-determining the set of identification values and/or the corresponding transmission parameters of the frames of the second type, either statically or dynamically, in a configuration table, preferably by self-learning;

-a configuration table is stored in a content addressable memory, each identification value representing an address in the memory;

-the switch is configured to apply at least one filtering operation on the input and/or output of each frame according to the transmission parameter corresponding to the identification value of the frame; and

-the switch is configured to use best effort techniques (best effort techniques) for transmitting each frame of the second type.

The invention also relates to an aircraft communication system comprising:

-a plurality of switches connected together to form one or more computer networks, each switch being as previously defined; and

-a plurality of devices, each device being a sender and/or a receiver of frames of the first type and/or of the second type and being connected to at least one switch.

The invention also relates to a transmission method realized by the switch, which comprises the following steps:

-receiving a frame;

-determining an identification value of the received frame;

-determining a transmission parameter in the configuration table corresponding to the identification value; and

-exchanging a received frame between the input port and the at least one output port based only on the determined transmission parameters, independent of the type of the frame.

Drawings

These features and advantages of the invention will become clear from the following description, given by way of non-limiting example only and made with reference to the accompanying drawings, in which:

FIG. 1 is a schematic illustration of an aircraft including an ARINC 664P7 type aircraft network and an IEEE 802 type aircraft network;

FIG. 2 is a schematic illustration of a communication system implementing the aircraft network of FIG. 1 in accordance with the present invention;

fig. 3 is a schematic diagram of a switch that is part of the communication system of fig. 2, in accordance with the present invention; and

fig. 4 is a flow chart of a transmission method according to the invention; the method is implemented by the switch of fig. 3.

Detailed Description

In the following, any reference to a specification or standard, in particular a computer standard, refers to the general principles of the standard, which are well known to those skilled in the art and are independent of different versions of the standard, unless explicitly stated otherwise.

Fig. 1 illustrates an aircraft 10, such as an airplane.

The aircraft 10 includes an aircraft network 12 of the ARINC 664P7 type and an aircraft network 14 of the IEEE 802 type.

The aircraft network 12 allows sensitive data to be transmitted between different aircraft systems. Sensitive data refers in particular to any data whose loss or transmission delay may have an impact on the safety of the aircraft 10.

The aircraft network 14 allows less sensitive data to be transmitted than the aircraft network 12. Thus, for example, the data corresponds to maintenance data exchanged between the aircraft 10 and the ground and/or functional data exchanged with the crew and/or passenger entertainment data and/or any other type of data.

The digital data streams through the two networks 12, 14 are in the form of frames of a first type and frames of a second type, respectively.

Thus, the first type of frame conforms to an ARINC 664P7 type protocol, while the second type of frame conforms to an IEEE 802 type protocol.

In particular, "IEEE 802 type protocol" refers to a protocol in the IEEE 802 family of protocols. Such a protocol is for example a protocol of the 802.3 ethernet type, or a protocol of the 802.1xxx type, i.e. a protocol of the IEEE 802.11WiFi type, a protocol of the 802.1Q type or a protocol of the MilStd 1553 type.

Each frame transmitted in the corresponding network 12, 14 includes an identification field.

In the described example, this identification field is included in the header of the frame and forms, for example, a field called "MAC DEST".

As known per se, the MAC DEST field indicates the MAC address of the destination device of the corresponding frame.

Each identification field takes an identification value which, in the example described, then corresponds to the MAC address of the corresponding destination device of the frame.

According to other examples of embodiments, the identification field is formed by any other field of the header of the frame, for example a MAC SOURCE field indicating the MAC address of the device sending the corresponding frame.

According to a further example of embodiment, the identification field is formed by at least a part of a useful data field of the frame.

In general, an identification field of a frame should be understood as any field of a frame that allows to determine the switching rules of the frame within a given switch, as will be explained later.

The set of frames of the first type having the same identification value forms a single stream of the first type, and the set of frames of the second type having the same identification value forms a single stream of the second type.

In other words, each stream of each type is formed by a set of frames having the same identification value. Thus, the identification field of each frame also has an identifier of the stream associated with the frame.

According to the invention, the aircraft networks 12 and 14 are implemented by the same physical aircraft communication system 20.

An example of such an aircraft communication system 20 is shown in fig. 2.

Thus, referring to the figure, the communication system 20 includes a plurality of switches 22A, … …, 22N and a plurality of devices 24A, … …, 24M. The number of these different components and the way in which they are interconnected may of course vary according to the example.

Each device 24A, … …, 24M, also referred to as an "end system," is integrated into the aircraft system and ensures communication of the system with the networks 12, 14.

Thus, each device 24A, … …, 24M may be a transmitter and/or receiver of digital data, depending on the aircraft system into which it is integrated.

Further, at least some of the devices 24A, … …, 24M may belong only to the network 12 or only to the network 14. In this case, such a device is capable of transmitting and/or receiving only digital data from the network. At least some of the other devices 24A, … …, 24M may belong to both networks 12 and 14, so long as they are capable of sending and/or receiving digital data from both networks.

Each device 24A, … …, 24M is connected to at least one of the switches 22A, … …, 22N via a transport and at least one port of the switch. The transmission means have for example twisted pair cables or any other type of cable allowing a bidirectional data transmission or even a wireless link transmitting digital data via radio waves.

For devices 24A, … …, 24M, each transmission means may belong to only one of networks 12 and 14, or to both networks 12 and 14. This depends in particular on the nature of the connection of the respective transmission means of the devices 24A, … …, 24M to the respective network.

Within the corresponding network 12, 14, each device 24A, … …, 24M is identified by its MAC address. In particular, in the case of an ARINC 664P7 type network 12, multiple MAC addresses may be associated with the same device 24A, … …, 24M. Each of these addresses corresponds to a virtual link to that device 24A, … …, 24N.

In the case of an IEEE 802 type network 14, in a broad sense, a single MAC address ("unicast" address) is associated, for example, with each corresponding device, but there are also MAC addresses of the "multicast" and "broadcast" type that the device must be able to receive.

Thus, when the same device belongs to both network 12 and network 14, it may be associated with a MAC address of network 14 (a "unicast" type) and one or more MAC addresses of network 12.

The switches 22A, … …, 22N are connected to each other by transmission means also having, for example, twisted pair cables or any other type of cable allowing bidirectional data transmission or even wireless links transmitting digital data via radio waves.

The switches 22A, … …, 22N are, for example, substantially similar to each other. Therefore, hereinafter, only the switch 22A will be explained in detail with reference to fig. 3.

Thus, referring to this fig. 3, the switch 22A includes a plurality of input ports 31, a plurality of output ports 32, a configuration table 33, and a control and switching device 34.

Each input port 31 is capable of receiving frames of the first type and/or frames of the second type.

Each output port 32 is capable of transmitting frames of the first type and/or frames of the second type received via the input port.

The configuration table 33 is used to determine switching rules within the switch 22A.

To this end, the configuration table 33 is stored in a dedicated memory of the switch 22A and includes a list of identification values and, for each identification value, transmission parameters for the frame having that identification value. These transmission parameters are defined by each flow that may circulate through the switch 22A.

According to an advantageous example of embodiment of the present invention, the memory dedicated to the switches storing the configuration table is of the CAM type. In other words, the Memory is implemented according to CAM (Content Addressable Memory) technology, which means that this Memory is Content Addressable.

According to this example, the memory of the switch 22A is initialized with a list of identification values. In particular, this means that each identification value represents one memory address associated with a storage field comprising a transmission parameter corresponding to the identification value. This then makes the search for the identification parameter corresponding to a given identification value extremely fast, even almost instantaneous.

In one embodiment, the list of identification values is statically determined. This means that the list is determined at the system design stage and cannot be modified during its operation. It is therefore the intended route for each type of frame.

According to another embodiment, at least some of the identification values in the list are dynamically determined. That is, these values may be deleted or added during operation of the system 20. In this case, these identification values are only associated with the second type of stream. It should be noted that when a CAM memory is used, addresses in the memory may be dynamically added or deleted as identification values are added or deleted.

For the identification values of the first type of frame, i.e. the identification values of the ARINC 664P7 flows, these identification values can only be statically defined in order to guarantee the certainty of the network 12.

The transmission parameters have the same nature for each identification value and are clearly independent of the protocol of the frames of the corresponding stream. In other words, for each identification value, the transmission parameters advantageously consist of the same number of parameters ordered in the same way, and this independently of the protocol of the corresponding stream.

For each identification value, the transmission parameters include at least one timing period of a frame of the corresponding flow and at least one output port 32 of the frame of the flow.

The timing period then defines the timing of the frames of the stream corresponding to the minimum transmission interval of two consecutive frames of the same stream.

For the first type of flow, the timing period is referred to as a "BAG" (i.e., "bandwidth allocation gap"). The timing may define the authorized bandwidth of the corresponding flow.

Thus, according to the invention, a timing period is also associated with the second type of stream. These values may be equal to predetermined values (e.g., 0) or different values. In this second case, the flows of the second type are then called "BAGged" because attributes similar to those of the flows of the first type are associated with these flows of the second type. In this case, a predetermined bandwidth may also be associated for each second type of flow.

The bandwidth may be determined, for example, using one of the methods described in FR 1874166.

In various examples of this embodiment, for each identification value, the transmission parameter further defines at least one element selected from the group consisting of:

jitter (tolerance) of the frame with the identification value.

-an input port of a frame having the identification value.

-the priority of the frame having the identification value.

-the maximum size of the data packet transmitted by the frame having the identification value.

-the minimum size of a data packet transmitted by a frame having the identification value.

-an identifier of a group of output ports.

-the life cycle of the frame.

For example, the priority of each frame of the first type is determined, for example, higher than the priority of each frame of the second type. According to an example of embodiment, the priority of each frame of the first type is determined to be higher than a predetermined threshold, while the priority of each frame of the second type is determined to be lower than or equal to the same threshold.

With regard to the identifiers of a group of output ports, it is indeed possible to define and associate the identifiers with these groups, so that frames of the "broadcast" type, for example, are switched to only some of all the output ports of a given switch. This makes it possible to create multiple subnets in the same network.

As with the list of identification values, the transmission parameters for the first type of stream are statically determined.

For the transmission parameters related to the second type of stream they are determined statically and/or dynamically.

In particular, when at least some of these parameters and/or corresponding identification values are dynamically determined, this may be done by self-learning. According to an example of embodiment, a predetermined output port may be associated with each incoming frame of the second type whose identification value is not included in the list of identification values. In this case, the identification value may be included in a list with corresponding output ports.

According to an example of embodiment, the self-learning is applied only to certain input ports 31. This means in particular that the transmission parameters of a frame whose identification value is not included in the configuration table 33 are determined dynamically when it is received by such a predetermined input port. When such a frame is received by the other input port 31, it is discarded.

According to another example, the switch 22A associates at least one input port 31 with default transmission parameters. Thus, in this case, each frame received via such an input port 31 is switched to one or more output ports 32 according to such default transmission parameters.

According to yet another example, the switch 22A associates only the default transmission parameters with frames whose identification values are not included in the configuration table 33.

The control and switching means 34 allow to control the operation of each input port 31 and output port 32 and, as shown in fig. 3, are for example in the form of a central unit connected to each of these ports.

According to another example of this embodiment, the control and switching means 34 are at least partially distributed between the ports 31, 32 and thus allow local control of the operation of each of these ports.

The control and switching means 34 also allow frames to be switched within the switch 22A between each input port 31 and one or more output ports 32 according to the transmission parameters of the corresponding flows in the configuration table 33. This is done using only the corresponding transmission parameters, without distinguishing the type of stream, i.e. the protocol of the frame.

In other words, the control and switching means 34 allow to switch each frame between the input port 31 and the at least one output port 32, independently of the protocol of the frame, based only on the transmission parameters corresponding to the identification fields of the frame in the configuration table 33.

In particular, for the frames of the first type of flow, the control and switching means 34 allow each frame to be switched between the input port 31 and one or more output ports 32, the one or more output ports 32 being determined in the corresponding transmission parameters.

For the frames of the second type of flow, the control and switching means 34 allow each frame to be switched between the input port 31 and one or more output ports 32, the one or more output ports 32 being determined in the corresponding transmission parameters. Thus, for this type of frame, the control and switching means 34 allow, for example, the implementation of "broadcast" or "multicast" techniques.

The control and switching means 34 are configured to process each frame according to its priority, which is defined in the corresponding transmission parameters.

The control and switching means 34 are also configured to apply at least one filtering operation to the input of each frame according to the transmission parameters of the stream of that frame.

Such filtering operations are applied, for example, to each input port 31 and include, for example:

-identifying the identification value of the corresponding frame and rejecting the frame if its identification value is not expected according to the list of identification values of the configuration table 33; and/or

Identify the size of the corresponding frame and reject it when its size exceeds a threshold determined according to the corresponding transmission parameters of the configuration table 33.

Advantageously, according to the invention, such a filtering operation is performed on each incoming frame, independently of the type of the frame.

The control and switching means 34 may also be configured to control the frame of the first type according to a timing period defined by a corresponding parameter of the configuration table 33, and, when it differs from a predetermined value, optionally to control the frame of the second type according to a corresponding timing period.

According to one embodiment, the control and switching means 34 are also configured to apply at least one filtering operation to the output of each frame according to the transmission parameters of the flow of this frame.

Thus, for example, a filtering operation may be applied to the output that drops any frames having a lifetime greater than a predetermined threshold. In this case, the lifetime of a frame may be determined, for example, as the difference between the time the frame leaves the switch and the time the frame enters the switch.

By using these control and switching means 34, the switch 22A is able to implement the transmission method according to the invention, which will now be described with reference to fig. 4, which shows a flow chart of its steps.

Initially the configuration table 33 is considered to be formed and the communication system 20 is in operation.

In step 110, switch 22A receives a frame through one of its input ports 31.

In a next step 120, the switch 22A determines the identification value of the frame. In particular, the identification value is determined from the header of the received frame, in particular from the MACD EST field.

In a next step 130, the switch 22A determines the transmission parameters in the configuration table 33 corresponding to the identification value.

In a next step 140, switch 22A applies at least one previously defined filtering operation to the received frame.

When the received frame is not accepted after performing the filtering operation, it is discarded in step 145.

Otherwise, the switch 22A performs step 150 in which it switches the received frame between the input port and the at least one output port based only on the determined transmission parameters, regardless of the type of the frame. After the frame is received by the corresponding output port(s), then further filtering operations as defined above may be applied.

Of course, this transmission method may be performed in the same manner by any of the other switches 22B, … …, 22N.

Thus, it is envisioned that the present invention has a number of advantages.

First, the present invention makes it possible to use the same physical components (i.e. the same transmission means, the same switches and the same input and output ports) to achieve a mix of ARINC 664P7 and IEEE 802 type networks.

This then significantly reduces the footprint and weight of the networks 12 and 14 on the aircraft 10.

Finally, the switches of the communication system are configured to process frames independent of the type of frame (i.e., independent of the protocol of the frames). Thus, the operation of each switch is the same for each frame, and therefore there is no need to distinguish between frames of different protocols. Of course, the transmission parameters are determined according to the corresponding protocol, but from the point of view of the switch, all frames are processed in the same way according to the associated processing parameters.

Furthermore, the use of a CAM memory initialized with identification values makes it possible to search for corresponding transmission parameters particularly quickly in comparison with the search methods conventionally used in the prior art (e.g. search by binary).

This then allows the operation of each switch in the communication system to be more optimized.