DE102008012393A1 - Method for the dynamic reservation of frequency subareas - Google Patents

Abstract

The invention relates to a method in which frequency subareas (S1, S2, S3) of a frequency band (FB) are dynamically reserved by a plurality of communication systems. In this case, the frequency band (FB) is used by these communication systems for transmitting messages and / or data and is subdivided into a plurality of frequency subareas (KA, KB, S1, S2, S3). From a reserved communication system, which is entitled to use the frequency band (FB), a frequency sub-range (S1, S2, S3) is selected and an availability of this frequency sub-range checked (1, 21, 22). Then a so-called Allokierungsnachricht over this frequency sub-range (S1, S2, S3) is sent from the reserving communication system (3). Then, collision-free reception of this allocation message is checked (4) and, in the event of collision-free reception, the frequency division area (S1, S2, S3) is marked as reserved by the reserving communication system (51). The method first checks whether a corresponding frequency subarea (S1, S2, S3) is free for transmission by a reserving communication system. As a result, especially in the case of satellite communication, where bandwidth is expensive, the available frequency subareas (S1, S2, S3) can be utilized much more efficiently than with a fixed assignment.

Description

Technical area

The The invention relates to a method in which frequency subareas, so-called slots, a frequency band are dynamically reserved. The frequency band is transmitted by several communication systems used by messages and / or data and can be divided into several frequency subranges be divided.

State of the art

Under A communication system usually becomes a device for transmitting of messages, such as voice information, picture information, Video information or other data, with electromagnetic waves over one Transport route understood. The communication system is falling apart in an application system and in a transport system. From the transport system will the transport route between sending and receiving stations to disposal put, being a transfer the messages, for example, wired (for example, via a Line) or wirelessly (eg via a radio interface) can take place. The application system sets This transport ahead and interprets the transported messages in a certain way (eg language, image, data, etc.), to make them accessible and accessible to the participating stations to make usable.

Becomes from a wireless transmission the news goes out, so it can be with the sending and receiving stations depending on the specific configuration of the communication system - for example Cellular or satellite communication system - to various subscriber stations, Network-end radio stations (eg repeaters, etc.), base stations, Ground stations or transponders act. A radiating electromagnetic Waves, which contain the news, take place with so-called Carrier frequencies, in a for lie the respective communication system provided frequency band.

One Frequency band is a coherent frequency range, which by the same transmission characteristics distinguished. A frequency band may be in contiguous frequency subranges with a defined bandwidth - so-called Slots - divided be, with these slots z. B. individual communication systems z. B. be assigned by contract and then only by these communication systems for transmission can be used by messages. A frequency band is defined by an upper and lower frequency. Certain communication systems (eg satellite communication system, etc.) certain frequency bands are used. So become the example for the satellite communication the so-called C-band from 4 GHz to 8 GHz or the so-called K-bands, which are in the frequency range from 12.5 GHz to 40 GHz used.

From Satellite communication is then spoken when by the communication system for a transmission of messages between so-called ground stations with transmitting and / or Receiving devices (eg antennas, etc.) one or more satellites be used. A satellite communication system usually sets from a so-called ground segment or ground segment and a so-called space segment or space segment together. The ground segment includes all components that are on the ground for the purpose of satellite communications are installed such. B. ground stations with their transmitting and / or Reception facilities (uplinks and downlinks) and their connections to other ground stations or gateway stations for connection with other communication systems (eg fixed networks, mobile networks, Etc.).

The Space or space segment is that part of the satellite communication system, which is in space. That is, it includes all facilities in orbit such. B. the satellite with his or her transponders.

One Uplink designates a transmission direction in the satellite communication from a sending ground station to a satellite, so an uplink. The opposite direction - so from the satellite to a receiving ground station - is called Downlink called. Similarly, in mobile communication system for a radio link from a mobile station (e.g., mobile phone, etc.) to a base station also the term uplink and for a radio link of one Base station to a mobile station also the term downlink used.

Transponders, an artificial word from the terms transmitter and responder, are used for example in high-frequency transmission systems such. B. satellite communication systems used. From a transponder, the entire message processing processing of a transmitted message is accepted. An operation of a transponder, for example, referred to as transparent or Bent Pipe communication when receiving messages from the satellite and then directly z. B. be radiated again in a different frequency. That is, in the Bent Pipe communication, messages are sent from a ground station to the satellite or to the corresponding transponder of the satellite, from which the to are amplified and re-radiated at a different frequency in an area corresponding to a radiation angle of the satellite antenna to the earth.

For the uplink or the downlink to transfer of messages, certain frequency bands are available, which for example are predetermined by the respective transponder of the satellite. These frequency bands can in coherent Frequency subranges with defined bandwidth (slots) divided become. Usually are then those communication systems or their operators, of which certain satellites for transmitting of messages and / or data used by the operator of the Satellites certain slots for messaging z. B. assigned by contract. This will make the use of the frequency band on the transponder of the satellite to multiple communication systems.

A similar Approach is known for example from the mobile sector. There is by a so-called regulator or state regulatory authority that for a cellular technology (eg Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), etc.) usable frequency band in coherent frequency subareas divided. These then become individual operators of mobile radio communication systems or mobile networks assigned by contract for use.

These Fixed assignment of frequency subareas to specific communication systems or to their operators, in particular in satellite communications, the disadvantage that the bandwidth - d. H. the difference between lower and upper frequency of the from a particular communication system usable for transmissions frequency subrange is fixed. Used by a communication system for a message transmission a larger bandwidth needed so this communication system still remains on the basis the allocation limited bandwidth. That is also the case Case, if frequency subranges, what other communication systems have been assigned by these hardly used or unused stay. There is only the possibility that of an operator of a communication system only the him assigned slot can be reconfigured. Such a reconfiguration is However, time consuming, as they usually change configuration carried out by the operator of the satellite.

Presentation of the invention

Of the The invention is therefore based on the object of specifying a method through which a dynamic and demand-oriented allocation of Frequency sub-ranges allows becomes.

The solution This object is achieved by a method of the initially stated Art, wherein from a reserving communication system, a frequency subrange selected and an availability this frequency subrange checked becomes. Then, the reserving communication system becomes one mentioned Allokierungsnachricht about this frequency sub-range of the frequency band sent out and a collision-free reception of Allokierungsnachricht checked. at a collision-free reception is the frequency subrange of This communication system is reserved as a result of this use marked. The frequency band utilizing communication systems are thereby configured to give them a division of the frequency band is known in the frequency subareas.

Of the Main aspect of the invention proposed Procedure is that first of a communication system checked is whether a corresponding frequency sub-range or slot for a transmission is free and this is then reserved dynamically. This can, in particular in satellite communications, where bandwidth is expensive, the available Slots are used much more efficiently than a fixed one Allocation. additionally let yourself a protocol for make the dynamic reservation implementation easy so that it is of z. As manufacturers, operators of satellites or communication systems can be implemented in a simple way.

It is advantageous if from the reserving communication system one defined minimum use of the frequency sub-range ensured so that reservation of the frequency sub-range is maintained, since this ensures that use of this Frequency division by the active reservation of other communication systems is recognized.

It is also cheap when a reserved frequency subrange is released when no messages from a reserved communication system transfer more to this segment part because these frequency subranges are then different from other communication systems with higher bandwidth requirements or greater usage of messaging can be reserved.

It is also advisable if, in the case of non-collision-free reception, another allocating message is transmitted by the reserving communication system. A collision indicates that this frequency range is also transmitted by another communication system for a transmission should be reserved. Sending a further allocation message after a detected collision ensures that only one of the reserving communication systems makes a reservation and that the frequency subarea can be used without interference from the collision-free receipt of the allocation message.

In an advantageous further development of the method according to the invention becomes a period until the sending of another allocation message the type of collision encountered and prioritization dependent made. This has the advantage that by waiting for a Time duration further collisions depending upon constellation avoided or be prevented. The time until sending out another Allocation message, for example, on the nature of the collision depend. About these Time duration can also be controlled, which communication system at the next Reservation attempt is preferred. The control of the after one Collision taking place reservation of a frequency division is z. B. therefore important because in particular z. In satellite communications detecting a collision can take a relatively long time (eg at a geostationary Satellites about 500 ms).

at a further, alternative embodiment of the method according to the invention becomes a part of the frequency subregions of the frequency band the communication systems, from which the frequency band is used, permanently assigned. The has the advantage that the communication systems for messaging a so-called basic frequency subrange is always available. In addition, these basic frequency sub-ranges can easily be used for a controller a reservation of frequency subranges are used. This can easily control the reservation of frequency sub-ranges are carried out to collisions to prevent in the reservation.

To is used by the communication system on its base frequency subarea an announcement of Reservation of a verifiable frequency division announced. This The process must be done in a timely manner by all others Communication systems, of which also a reservation this frequency sub-range is sought, a shipment of its own Allocation message can be prevented. Both of these advantageous embodiment of the inventive method must of Each communication system, the base frequency sub-areas of each other communication systems evaluated and announcements for a reservation a frequency division - for a so-called Allocation - to be considered.

Preferably can serve as the field of application of the method according to the invention satellite communication, especially the so-called Bent Pipe communication, provided be. Especially for satellite communication bandwidth for message transmission is expensive, this can be achieved by the inventive method in a simple manner be used efficiently. When used in satellite communications exists as well the advantageous possibility for the Control of the reservation of frequency subregions of the frequency band to use a so-called terrestrial communication. A Such control has the advantage of negotiating the reservation without a big one communication delay the satellite communication can take place.

Brief description of the drawing

The Invention will now be described by way of example with reference to the accompanying drawings explained. Show it:

1 schematically in an exemplary manner a division of a frequency band in frequency sub-ranges for the inventive method

2 In an exemplary manner, the schematic sequence of a dynamic reservation of frequency sub-ranges of a frequency band

Embodiment of the invention

1 shows in schematic form a frequency band FB, which is used for example for communication between a ground station and a satellite or a satellite transponder. The exemplary frequency band is z. B. of two communication systems A, B, both of which for the sake of simplicity in the 1 are not shown, for z. B. satellite communication used. The frequency band FB is for this purpose in an exemplary manner in several frequency sub-areas KA, S1, S2, S3, KB, so-called slots, divided.

In this case, for example, the frequency subrange KA a first communication system A z. B. has been permanently assigned by the operator of the satellite. The frequency range KB has also been fixedly assigned to a second communication system B by the satellite operator. The frequency sub-area S1, S2, S3 represent so-called slots that are not assigned to either the first communication system A or the second communication system B fixed. These slots 51 , S2, S3 can therefore be temporarily and dynamically assigned to one of the two communication systems A, B, of which the frequency band FB is used. The Both communication systems A, B are configured so that they are aware of the division of the frequency band FB in the slots S1, S2, S3.

Alternatively, it is also possible that the frequency subareas KA, KB are not assigned to the two communication systems A, B using the frequency band FB. In this case, only slots S1, S2, S3, in which the frequency band FB is divided, are then used for communication. For the operation of the method according to the invention, the sequence in a schematic manner in 2 is shown and which will be described in the sequence, it is irrelevant whether there are gaps between the slots KA, S1, S2, S3, KB and in how many not dedicated slots S1, S2, S3, the frequency band FB is divided. The division of the frequency band FB must be known only to the communication systems A, B, of which this is used. This can be done by a corresponding configuration of the communication systems.

2 schematically shows the sequence of the method according to the invention, by each of which one of the dynamically assignable slots S1, S2, S3 can be assigned by a communication system - for example, the first communication system A - for transmitting messages due to additional bandwidth requirements. The number of slots S1, S2, S3 is irrelevant for a sequence of the method according to the invention. As a result, z. B. the sequence of the method with reference to the example slots S1, S2, S3, which already in 1 have been shown.

The method according to the invention begins with a starting step 1 in this starting step, a slot S1, S2, S3 for reservation is selected by a reservation communication system (eg, communication system A) which is not used by this communication system. In a second process step 21 is then checked whether this slot S1, S2, S3 is in use. This happens, for example, by checking the power density averaged over a time in this slot S1, S2, S3 against a threshold value. If it is determined that slot S1, S2, S3 is in use, then in a third method step 22 a new, not reserved by the reserving communication system itself used slot S1, S2, S3 selected for the reservation and turn the process steps 1 and 21 repeated.

In a fourth process step 3 the allocating message is sent over the selected slot S1, S2, S3 by the reserving communication system (eg communication system A). In a fifth process step 4 For example, the reserving communication system A checks whether the allocation message could be received without collision.

If no collision is detected, then in a sixth method step 51 the selected slot S1, S2, S3 from reserved communication system A marked as reserved. The reservation is made by use of transmitting messages without long interruptions through the slot S1, S2, S3 through the reservation communication system. In order to keep the slot S1, S2, S3 reserved, a reserved minimum use of the reserved slots S1, S2, S3 is ensured by the reserving communication system. This can be done, for example, by message transmission or by sending other content (eg, fixed patterns, etc.). A release of a reserved slot S1, S2, S3 is performed, for example, by an internal identification of the slot S1, S2, S3 as "not reserved" by the reserving communication system A and no further use of the slot S1, S2, S3. This slot S1, S2, S3 can then be marked as reserved by other communication systems, which are also entitled to use the slots S1, S2, S3.

Will in the fifth step 4 detects a collision, a reservation attempt is made by the reserving communication system A again. In this case, for example, in a seventh process step 52 waited for a certain period of time before a new reservation attempt is made. The length of the time depends on how the detected collision occurred.

For example, this can be be determined in which temporal sequence of reserving Communication system A and the other communication systems Allocation messages have been sent out. From every communication system can then z. B. with the next Reservation attempt the longer to be serviced, the later sent by him the Allocation message compared to the other communication systems has been. In satellite communication at geostationary satellites For example, detection of a collision may take about 500 ms. The duration until the repetition of the reservation attempt z. B. also for Prioritization of the communication systems used in terms of reservation become.

After waiting for the time is then in an eighth step 6 from the reserving communication system A another Allokierungsnachricht about the slot to be reserved S1, S2, S3 and then sent by repeating the third step 3 Checked whether a collision has occurred again or not. According to a He result of the third process step 3 then becomes the fourth process step 41 performed if no collision is detected, or it will then be the detection of a collision of the fifth and the sixth method step 42 . 52 repeated again.

The inventive method For example, in the field of satellite communications for two or - without changes the functioning - for several Communication systems are used. The inventive method is also for suitable for use in the field of mobile communications.

Claims (9)

Method for dynamically reserving frequency subareas (S1, S2, S3) of a frequency band (FB), the frequency band (FB) being used by a plurality of communication systems for transmitting messages, characterized in that - a frequency subarea (S1, S2 , S3) and an availability of this frequency subrange is checked ( 1 . 21 . 22 ), - that then from the reserving communication system an Allokierungsnachricht over this frequency sub-range (S1, S2, S3) is sent ( 3 ), That a collision-free receipt of the allocation message is checked ( 4 ), And that then, in the case of collision-free reception, the frequency subregion (S1, S2, S3) is marked as reserved by this communication system (S1). Method according to claim 1, characterized in that that from the reserving communication system a defined minimum use of the frequency sub-range (S1, S2, S3) is ensured to the Frequency division (S1, S2, S3) to keep reserved. Method according to one of claims 1 to 2, characterized a reserved frequency subrange (S1, S2, S3) is then enabled if there are no messages from a reserving communication system be transmitted more in this frequency subrange. Method according to one of claims 1 to 3, characterized in that in non-collision-free reception by the reserving communication system, a further Allokierungsnachricht is sent ( 6 ). Method according to Claim 4, characterized in that the time duration until the sending of a further allocation message is made dependent on the type of collision that has occurred and a prioritization ( 52 ). Method according to one of claims 1 to 5, characterized that a part of the frequency sub-ranges (KA, KB) of the frequency band (FB) the communication systems of which the frequency band (FB) is used, be assigned permanently. Method according to Claim 6, characterized that for a control of a reservation of frequency subregions (S1, S2, S3) of a communication system permanently assigned part of the frequency sub-ranges (KA, KB) of the frequency band (FB) is used. Method according to one of claims 1 to 7, characterized that as a field of application satellite communications, in particular the so-called Bent Pipe communication is provided. Method according to claim 8, characterized in that that for the control of the reservation of frequency subregions (S1, S2, S3) of the frequency band (FB) a so-called terrestrial communication is used.