DE102013210307A1 - Communication device, system and method for communication between a communication device and at least two base stations - Google Patents

Abstract

It is an object of the present invention to provide a system which enables the most efficient connection transfer between two base stations. This object is achieved by a communication device which comprises: - at least one position determination unit for determining position data (PosData) of the communication device (40); - at least one radio transmission / reception unit (41) for communication with at least one first (10) and at least one second (20) base station; - at least one transfer parameter determination unit (42) for determining transfer parameters, the transfer parameter determination unit (42) for determining the transfer parameters transmitting the position data (PosData) to one of the base stations and / or using the transfer parameters in a memory (23; 43) the position data (PosData) is identified, the position data (PosData) being linked to road data (StrData).

Description

The invention relates to a communication device for communicating with at least two base stations, a system for providing communication between a communication device and at least two base stations and a corresponding method.

In mobile telecommunications networks, such. As GSM (Global System for Mobile Communications), UMTS (Universal Mobile Telecommunications System) or LTE (Long Term Evolution), it is necessary that mobile terminals (UE) during a call or a data connection without interruption of this connection from a radio cell in one others can change. This process is called handover.

The transfer of the connection can be assessed on the basis of key performance indicators (also referred to as Key Performance Indicator or KPI). This may include information regarding the failure of the radio link (also referred to as Radio Link Failure or RLF) or the frequency of a handover / handover ping-pong (also referred to as a handover ping-pong rate or HPR). HPR describes the frequency of consecutive handovers between two remote communication cells. The KPIs depend on several parameters that can control the handover process. This is, for example, the TTT value or time-to-trigger value, which specifies a time interval which has to wait to trigger a handover or a handover before the handover is actually executed. Another relevant parameter is the Handover Offset Margin (HOM value). This HOM value is a difference value of the signal strength of the currently operating radio cell and the future radio cell measured on the terminal. A transfer is only initiated if the signal strength of the current radio cell is worse by at least the difference value over a given time interval (eg TTT value).

Currently known state of the art with regard to handover methods is based on the fact that handover or transfer parameters (TTT value and HOM value) are allocated globally or depending on the radio cell. Accordingly, only cell-specific transfer parameters are assigned to a radio cell, so that it is still possible for the above-mentioned handover ping-pong effects or for failures in the radio connection, that is, radio link errors.

It is an object of the present invention to improve the handover. In particular, a communication device is to be provided which enables efficient and uninterrupted communication with at least two base stations, in particular for the 3GPP LTE standard. Furthermore, a corresponding system and a corresponding method should be specified.

This object is achieved by the communication device according to claim 1.

• – mindestens eine Positionsermittlungseinheit zur Ermittlung von Positionsdaten des Kommunikationsgeräts;
• – mindestens eine Funksende-/empfangseinheit zur Kommunikation mit mindestens einer ersten und mindestens einer zweiten Basisstation;
• – mindestens eine Übergabeparameter-Ermittlungseinheit zur Ermittlung von Übergabeparametern.

In particular, the object is achieved by a communication device, preferably a (mobile) terminal, comprising:

• - At least one position detection unit for determining position data of the communication device;
• - At least one radio transmitter / receiver unit for communication with at least a first and at least one second base station;
• - At least one transfer parameter determination unit for determining transfer parameters.

According to the invention, the transfer parameter determination unit determines the position data for determining the transfer parameters to one of the base stations and / or the transfer parameters are identifiable in a memory on the basis of the position data with the aid of the transfer parameter determination unit, the position data being associated with road data.

The transfer parameter determination unit may be designed such that this determination unit requests the required transfer parameters from a base station. The transfer parameters can be determined in or from a base station and transmitted to the communication device.

Preferably, this communication device is mobile and / or component of a mobile device (eg of a vehicle). The communication device can therefore be a mobile communication device, for. As a mobile phone, or even an on-board computer of a vehicle with appropriate interfaces.

The position detection unit may receive data from an external device to determine the position or independently derive corresponding position data. A corresponding position determination unit can be a module belonging to a global navigation satellite system, that is to say a GNSS module, such as a GNSS module. As a GPS module or a GLONASS module or a Compass module according to Chinese standards, which is built into the communication device or supplies corresponding data to the communication device. The position data may be, for example, geographic data or data indicating a particular road, a specific road section, a specific city, and / or a specific country.

The radio transmitter / receiver unit is used for communication with at least two base stations, wherein the communication with at least two base stations, which are geographically remote from each other, preferably without interruption, ie consecutive consecutive time, is performed. Accordingly, a handover or a handover from a first base station to a second base station is necessary. The transfer of the connection (or handover) is made on the basis of transfer parameters. At least one transfer parameter determination unit is provided for determining the transfer parameters.

According to the invention, the transfer parameter determination unit transmits the position data to one of the base stations for determining the transfer parameters and / or identifies the transfer parameters in a memory on the basis of the position data. The position data are in turn linked to road data, wherein the transfer parameters can be identified for example on the basis of the imaged road data.

In a further embodiment of the invention, the communication device may comprise a detection unit for detecting the movement speed data and / or the travel direction data of the communication device. The travel speed data and / or travel direction data of the communication device are taken into account in the determination of the transfer parameters. Accordingly, the detection unit for detecting said data is signal-connected to the transfer parameter determination unit, so that the data acquired by the detection unit can be transferred to the transfer parameter determination unit. For example, if the communication device is part of a vehicle, the travel speed data is the speed of the vehicle. The travel direction data accordingly correspond to the direction of travel of the vehicle. Thus, when determining or determining the transfer parameters, speed and direction data can be included for the first time.

• – Daten bezüglich eines Straßenverlaufs und/oder
• – Daten bezüglich der Funkwellenausbreitung mindestens einer der Basisstationen und/oder
• – Daten bezüglich einer, einer Straße auf welcher sich das Kommunikationsgerät befindet, zugeordneten Höchstgeschwindigkeit und/oder
• – Daten bezüglich einer, einer Straße auf welcher sich das Kommunikationsgerät befindet, zugeordneten Durchschnittsgeschwindigkeit.

According to the invention, the transfer parameter determination unit takes into account, for example, the following data when determining the transfer parameters:

• Data relating to a course of the road and / or
• Data concerning the radio wave propagation of at least one of the base stations and / or
• Data relating to a maximum speed associated with a road on which the communication device is located and / or
• Data relating to an average speed associated with a road on which the communication device is located.

In one possible embodiment of the invention, data relating to the radio wave propagation of at least the currently operating base station and the intended future base station are taken into account when determining the transfer parameters.

Accordingly, the average speeds of the vehicles determined for a specific road or a specific road section and / or the maximum speeds valid for the road or for road sections can be stored in a memory. If the communication device is located at a certain position of a particular road, this position is clearly associated with an average speed and / or maximum speed stored in the memory. Furthermore, data relating to the radio wave propagation of one or more base stations can be assigned to each position or each position data set. Information about the course of the road is of great benefit in that it can be used to calculate the likely position of a communication device on a road.

The transfer parameters determined with the aid of the transfer parameter determination unit are the triggering time interval, in particular the TTT value and / or radio quality information, in particular the HOM value. The HOM value describes a difference value of the signal strength of the currently operating one Radio cell and the future radio cell. A transfer is only initiated if the signal strength of the current radio cell is worse by at least the difference value over a given time interval (eg TTT value). Preferably, the transfer data are sets of TTT values and HOM values, ie, a given transfer parameter set is assigned taking into account road data and optionally taking into account the travel speed data and the travel direction data, a specific transfer parameter set: (T; H ).

In a further embodiment of the invention, the communication device has a measuring unit for measuring quality data of a communication with the first base station and / or at least one signal of the first base station, wherein the communication device initiates a change of a primary communication from the first to the second base station when the quality data, preferably via a / the tripping time interval, a / the radio quality indication according to the transfer parameters.

Due to the determination of the transfer parameters with the aid of position data taking into account road data and optionally with the aid of travel direction data and speeds, a satisfactory determination of transfer parameters is for the first time possible in such a way that ping-pong effects and RLF effects are largely reduced.

The transfer parameter determination unit is further preferably signal-connected to the position determination unit and the radio transmission / reception unit, so that the transfer parameters can be transmitted to the radio transmission / reception unit.

The above object is further achieved by a system comprising at least two base stations, which span at least two remote communication cells or radio communication cells and are designed for radio communication with at least one communication device.

The described system comprises at least one base station with a receiving unit for receiving position data of the communication device. Accordingly, the position data of the communication device determined by the position determination unit can be transmitted to the or a base station. In addition, the system according to the invention comprises at least one memory unit for storing a plurality of transfer parameters as a function of position data, wherein the system is configured to select transfer parameters from the position data for the at least one communication device.

• – Daten bezüglich eines Straßenverlaufs und/oder
• – Daten bezüglich der Funkwellenausbreitung mindestens einer der Basisstationen und/oder
• – Daten bezüglich einer, einer Straße auf welcher sich das Kommunikationsgerät befindet, zugeordneten Höchstgeschwindigkeit und/oder
• – Daten einer, einer Straße auf welcher sich das Kommunikationsgerät befindet, zugeordneten Durchschnittsgeschwindigkeit

berücksichtigen.In a further embodiment of the invention, the system may select the transfer parameters

• Data relating to a course of the road and / or
• Data concerning the radio wave propagation of at least one of the base stations and / or
• Data relating to a maximum speed associated with a road on which the communication device is located and / or
• Data of an average speed assigned to a street on which the communication device is located

consider.

In a further embodiment of the invention, data relating to the radio wave propagation of at least the currently operating base station and the intended future base station are taken into account in the selection of the transfer parameters.

It is thus possible that a communication device determines its position and uses the memory to determine the associated road data and from this derives the transfer parameters. Moreover, it is possible for the base station to determine the transfer parameters of the communication device by adding the road data on the basis of the transmitted position data and to communicate these to the communication device.

Accordingly, at least one base station or the base station can have a transmission unit for transmitting transmission parameters to the at least one communication device as a function of the position data.

Furthermore, it is conceivable that the data acquired with the aid of the detection unit can be transmitted to one or more base stations with regard to the travel speed and / or direction of travel of the communication device.

In summary, it is theoretically possible that the transfer parameters can be transmitted in a centralized or decentralized manner.

In a centralized embodiment of the aforementioned system or communication device, at least one base station (eNB) has a memory for storing a digital map with transfer parameters stored therein. The communication device (UE) transmits the position or GNSS data to the base station, so that the base station can make a selection with respect to the transfer parameters on the basis of the position data and the associated road data. The transfer parameters or the specific TTT value and / or the specific HOM value is then transmitted by means of a transmitting unit from the base station to a / the communication device.

In a decentralized embodiment of the invention, one or the base station transmits the digital map with transfer parameters stored therein to the (mobile) terminal or communication device. With the help of the transfer parameter determination unit, the optimal transfer parameters can be determined on the basis of the position data determined by the position determination unit and the road data associated therewith.

The object mentioned at the outset is furthermore achieved by a vehicle having a communication device, as has already been described above. This vehicle may include a navigation system that determines or provides the position data.

There are similar advantages as they have already been described in connection with the system or the communication device.

• a) Aufbauen einer Sprach- und/oder Datenverbindung zwischen dem Kommunikationsgerät und der ersten Basisstation;
• b) Bestimmen/Empfangen von Positionsdaten des Kommunikationsgerätes, wobei die Positionsdaten Straßendaten umfassen,
• c) Bestimmen/Empfangen von Übergabeparametern anhand der Straßendaten;
• d) Übergabe der Sprach- und/oder Datenverbindung an die zweite Basisstation unter Berücksichtigung der bestimmten/übermittelten Übergabeparameter.

The object is furthermore achieved by a method for communication between a communication device and at least one first and at least one second base station. This method can be performed with communication devices as already described. The at least first and the at least second base stations are preferably associated with a system as already described. The method may include the following steps:

• a) establishing a voice and / or data connection between the communication device and the first base station;
• b) determining / receiving position data of the communication device, the position data comprising road data,
• c) determining / receiving transfer parameters based on the road data;
• d) transfer of the voice and / or data connection to the second base station, taking into account the specific / transmitted transfer parameters.

• e) die Fortbewegungsgeschwindigkeitsdaten und/oder die Fortbewegungsrichtungsdaten des Kommunikationsgerätes erfasst/empfangen, wobei diese Geschwindigkeits- bzw. Richtungsdaten bei der Ermittlung der Übergabeparameter berücksichtigt werden.

Optionally be in one step

• e) the movement speed data and / or the Fortbewegungsrichtungsdaten of the communication device detected / received, these speed or direction data are taken into account in the determination of the transfer parameters.

The transfer parameters in step c) are a release time interval for the transfer, in particular a TTT value, and / or a radio quality specification, in particular a HOM value, which are determined / received.

Some of the data required for the communication between at least one communication device and at least two base stations (position data, road data, transfer parameters) can be stored in a decentralized or centralized manner. In one embodiment, the road data and transfer parameters are stored in the base stations. Even a system-superordinate memory is theoretically conceivable.

• f) Übermittlung des/eines TTT-Werts und/oder des/eines HOM-Werts von einer/der Basisstation an ein/das Kommunikationsgerät und;
• g) Modifikation des TTT-Werts und/oder des HOM-Werts vom Kommunikationsgerät.

Thus, the method may further comprise the following steps:

• f) transmitting the TTT value and / or the HOM value from a base station to a communication device and;
• g) Modification of the TTT value and / or the HOM value of the communication device.

The TTT and HOM values transmitted or transmitted to a communication device can be modified, for example, on the basis of the travel speed and / or the direction of travel. The speed of movement refers to the road on which the communication device where the average speed and / or maximum speed of the road can be taken into account when modifying the values. The direction of movement can be determined by the course of the road on which the communication device is located.

• h) der/ein modifizierter TTT-Wert und/oder ein/der modifizierte HOM-Wert zusammen mit Übergabequalitäten, die die Qualität der Übergabe von der ersten zur zweiten Basisstation angeben, gespeichert wird/werden.

Preferably, it is further provided in the method according to the invention that

• h) the modified TTT value and / or modified HOM value is / are stored along with transfer qualities indicating the quality of the transfer from the first to the second base station.

The storage of the modified values as well as the transfer qualities can take place both in a memory of the communication device and in a memory of the base station (s) and / or in a higher-level memory.

• i) Qualitätsmessung bezüglich der durchgeführten Übergabe des Kommunikationsgerätes in eine zweite Fernkommunikationszelle einer zweiten Basisstation anhand eines/des modifizierten TTT-Werts und/oder eines/des modifizierten HOM-Werts;
• j) Vergleich der gemessenen Übergabequalität mit gespeicherten Übergabequalitäten zur Optimierung zukünftiger Übergaben.

The method may further include the following steps:

• i) measuring the quality of the transfer of the communication device in a second remote communication cell of a second base station using a modified TTT value and / or a modified HOM value;
• j) Comparison of the measured handover quality with stored handover qualities to optimize future handovers.

If the measured transfer quality is better than the stored transfer qualities or the measured transfer quality does not violate the transfer qualities achieved, then the modified TTT value and / or the modified HOM value, which has led to or is associated with an improved transfer quality be stored, this storage has to be done in connection with the associated position data and / or road data and / or speed or direction data. The storage can be carried out in the communication device and / or in the base station and / or higher-level.

In a further embodiment of the invention, it may be provided that a threshold value is defined for a first transfer value and a second transfer value can be modified as desired and compared with stored transfer qualities. For example, for a modified TTT value, a threshold is defined and the HOM value is arbitrarily modified and compared with stored handover qualities. Consequently, a transfer value can be optimized or modified under the condition of another transfer value.

In one embodiment of the method according to the invention, the modification of a TTT value and / or a HOM value is an optimization, wherein R _out (θ) under the proviso R _pp (θ) ≤ R is minimized. That is, the data loss rate R _out (θ) is minimized at a predetermined number of ping-pong handovers R _pp (θ).

at R is the ping-pong ratio to be achieved. Θ is a vector of m pairs of transfer parameters {H, T} such that θ: = (H ₁ , ..., H _m , T ₁ , ..., T _m ). Hereinafter, θ is defined as an amount {H, T} such that θ _{j is} a concrete pair of parameters with respect to a road j, {H _j , T _j } for i = 1, ..., 2m, j = i mod damn.

R _out is the proportion of the failure of a communication channel (channel outage ratio). R _pp , on the other hand, is the proportion of handover ping-pong events. Both ratios can be measured or collected by the base stations according to the invention, wherein

N _slots designates the number of all time slots counted after the occurrence of the A3 event, this A3 event being the time when a base station of an adjacent remote communication cell provides a better signal with a difference strength of HOM than the base station, which is used at the moment. N _out is the number of time slots which gives too bad a signal, so that the gemäß _min requirement is not reached within the fully counted time slots.

N _pp and N _ho refer to the number of ping-pong handovers or the number of handovers / handovers / handovers.

A handover state A3 usually occurs when δ ^{( t )} > H, where δ ^(t) = p _n ^(t) -p _s ^{( t )} . The probabilities of R _out and R _pp are labeled P _out and P _pp , where

The handover period, on the other hand, is defined as [t ₀ + 1, t ₀ + T], where t ₀ = time slot or time slot when A3 occurs. A3 regarding a ping-pong handover will occur at time t1.

P (t1) / PP (θ) concerns the likelihood of a ping-pong handover with -Δ (t) = p (t) / s -p (t) / n,
in which P (t1) / pp (θ) with respect to the probability of the occurrence of A3 at the time t _{1 may have} an approximate value, wherein the handover or the handover is triggered after the time T:

δ ^(t) relates to the RSRP difference (Reference Signal Received Power), where μ (δ ^{(t + r)} ) = H + M ^{(t + r)} (7) σ (δ ^{(t + r)} ) = C (8)

M ^{(t + r)} is dependent on the travel speed and the direction of travel of the communication device or the vehicle. On the other hand, C is a constant that denotes the variance of the RSRP difference and is based on a machine learning method.

wobei

wobei μ und σ der Mittelwert und die Varianz von δ^(t₀+r) und wobei μ' und σ' der Mittelwert und die Varianz von δ^(t₁+r) sind.Since the probability calculations according to formulas (4) and (6) can not be explicitly calculated, the first two times are used to derive the upper limits of
P (t₀) / out and P (t₁) / PP
used:

in which

where μ and σ are the mean and variance of δ ^{(t₀ + r)} and where μ 'and σ' are the mean and variance of δ ^{(t₁ + r)} .

verwiesen. Dabei betreffen y^(t) und φ^(t) jeweils die Signalstärke am Kommunikationsgerät gemäß eines Wellenausbereitungsmodells zum Zeitpunkt t und ein Random Signal zum Zeitpunkt t. Für die Berechnung von y^(t) werden die Fortbewegungsgeschwindigkeit und die Fahrtrichtung benötigt, wobei die Höchst- und Durchschnittsgeschwindigkeit und die Richtung der Straße, auf welcher sich das Kommunikationsgerät befindet, ausgewählt werden können. Des Weiteres sind Δy^(t) und Δφ^(t) jeweils y^(t) – y^(t-1) und φ^(t) – φ^(t-1). Die Subskripten s und n bezeichnen jeweils die bedienende Funkzelle und die vorgesehene Funkzelle.The optimization parameters P (t) / out (θ) and P (t) / pp (θ) are based both on the parameters H and T and on the parameter M, which in turn allows the travel speed and the direction of movement to be included in the optimization values. Concerning M ^{( t )} let:

directed. In this case, y ^(t) and φ ^(t) respectively relate to the signal strength at the communication device according to a wave preparation model at time t and a random signal at time t. For the calculation of y ^(t) , the travel speed and the direction of travel are needed, whereby the maximum and average speeds and the direction of the road on which the communication device is located can be selected. Further, Δy ^(t) and Δφ ^{(t) are} respectively y ^(t) -y ^{(t -1)} and φ ^(t) -φ ^(t-1) . The subscripts s and n respectively designate the serving radio cell and the intended radio cell.

Based on the formulas (9) and (10), a heuristic approach can be selected according to the invention in order to optimize the transfer parameters (T; H). Preferably, a road-specific optimization of the transfer parameters. This optimization can be carried out according to the invention on the basis of the following pseudo-algorithm.

The described devices can store transfer parameters that follow this optimization or make this optimization to improve the handover. Likewise, the methods described can resort to and / or generate correspondingly optimized values.

The invention will be described by means of several embodiments, which are explained in more detail with reference to figures.

Hereby show:

1 a system having a first and a second base station and a communication device, wherein the communication device is designed such that a communication between the communication device and both base stations can take place;

2 Components of a communication device;

3 a schematic representation of two base stations and two spanned Fernkommunikationszellen with a located in a remote communication cell communication device; and

4 An assignment table that assigns transfer parameters in each position in conjunction with acquired speeds and direction data.

In the following description, the same reference numerals are used for the same and like parts.

The 1 shows a system with a first base station 10 and a second base station 20 , Furthermore, there is a vehicle 30 intended. The vehicle 30 is located on a street in one of the base station 10 opened radio cell 11 , Also the second base station 20 spans a radio cell 21 on.

The vehicle 30 is configured such that it is compatible both with the first base station 10 as well as with the second base station 20 can communicate, in the embodiment according to 1 currently a communication - data and / or voice connection - between the first base station and the vehicle 30 is made. The vehicle 30 is located on a street leading towards the second base station 20 and thus in the direction of the second radio cell 21 leads. According to the inventive communication device or method according to the invention, transfer parameters are to be defined or determined so that a transfer of the vehicle 30 from the first radio cell 11 into the second radio cell 21 can be performed, this handover or handover is not necessarily at the limit 25 the two radio cells must be made. Rather, the invention uses the knowledge about the course of the road and / or the speed of the vehicle 30 and / or the maximum and / or average speed of the road to perform an optimal handover.

According to 2 becomes the vehicle 30 represented, this according to the invention a communication device 40 comprising, as shown, a radio transmitter / receiver unit 41 , a transfer parameter determination unit 42 and a memory 43 having. This store 43 can also be in the base station 10 or 20 or be designed to be superordinate. Likewise, the vehicle points 30 a GNSS module 50 on, the position data PosData to the communication device 40 supplies.

For example, this position data PosData can be an identification number that indicates a specific subsection of a specific street in a specific city in a particular country.

According to the invention is in the storage device 43 stored a road data allocation table, which makes it possible to link the position data with road data. The road data may be data relating to the course of the road and / or data concerning the radio wave propagation of the base station (s) and / or the road on which the communication device is located 40 or the vehicle 30 is located, assigned maximum speed and / or the, the road on which the vehicle 30 or the communication device 40 is located, assigned average speed and / or to trade road map data.

Thus, each position on a segment on a road is assigned both a prescribed maximum speed and a statistically determined average speed. The road or road map data can also be stored in the memory 43 be deposited. Optionally, the vehicle 30 a detection unit 60 to capture the current speed 61 of the vehicle and the direction of travel of the vehicle 62 exhibit. The data of the detection unit is sent to the communication device 40 , in particular to the transfer parameter determination unit 41 transfer, so that the Transfer parameters (T; H) depending on the position and the associated road data and the current speed and direction of movement of the vehicle can be determined. In a preferred embodiment of the invention are in the memory 43 for the respective road and / or for the respective road section already optimized transfer parameters stored. These transfer parameters can be calculated or determined in an iterative process.

In one embodiment, the communication device takes over 40 the task, the characteristic data of the road 71 (History, average speed, etc.). In another embodiment, a navigation system provides all or some of the characteristic data. Theoretically, it would also be conceivable that the digital road map of a navigation system contains the transfer parameters (H, T) and these continuously or on request to the communication device 40 supplies.

As in 3 represented, is the vehicle 30 on a street 70 , which from a first radio cell 11 into a second radio cell 21 leads. Also shown are the first base station 10 and the second base station 20 and another in the radio cell 11 located street 71 , The position shown (PosData) of the vehicle 30 is linked to street data (StrData). Accordingly, there is a maximum speed of 100 km / h at this position. By contrast, the statistically determined average speed is 82 km / h. In addition, memories associated with the respective base stations are 13 and 23 Road data relating to the course of the road and the radio wave propagation or radio wave strength of the base stations deposited. In the described embodiment, both the road data (StrData) and the transfer parameters are stored in the base station 13 and 23 saved. As already explained, it is also conceivable to have a part of this information or all information locally in the respective vehicle 30 or in a central database used by several base stations.

In the described embodiment, the position data (PosData) from the GNSS module 50 determined. Theoretically, however, it is also conceivable that the base station, the position data of the vehicle 30 determined. For example, the position data can be determined by triangulation on the basis of several base stations.

The vehicle 30 according to 3 comprises a detection unit 60 to capture the current speed 61 as well as the direction of movement 62 of the vehicle. The direction 62 thus states that the vehicle 30 in the street 70 to the east in the direction of the remote radio cell 21 emotional.

4 shows a corresponding allocation table for determining the transfer parameters based on which is determined at what time the vehicle 30 from the first radio cell 11 into the second radio cell 21 this transfer is not necessarily at the limit 25 has to be done between the two radio cells.

The assignment table shows by way of example that in connection with the radio cell 11 in which the vehicle is 30 located, eleven position data can result. In the present case, the position 3 taken in the radio cell. This position 3 stating that the vehicle is on the state highway 70 in the remote communication cell 11 located. Explicitly the vehicle is on the road 70 in the section 2 , The maximum permitted speed in this section is 100 km / h, with the average speed being 82 km / h. With the help of the registration unit 60 became the direction of travel 62 Determined "OST". The current speed 61 is 95 km / h, so that the transfer parameters TTT value = 1.7 and the HOM value = 3.0 are determined. The transfer parameters (1,7, 3,0) are transmitted to the radio transceiver so that an optimized handover or an optimized handover can be carried out.

Theoretically, it would be conceivable to measure the quality of the transfer of the vehicle 30 into the second radio cell 12 the second base station 20 the handover was performed on the basis of the modified TTT value of 1.7 and due to the modified HOM value of 3.0. Theoretically, it is conceivable that a comparison of the measured transfer quality with a stored transfer quality can then be carried out to optimize future transfers.

The individual embodiments described can be combined according to the invention in various ways.

LIST OF REFERENCE NUMBERS

10

First base station

11

First radio cell

13

Storage

20

Second base station

21

Second radio cell

23

Storage

25

border

30

vehicle

40

communication device

41

Radio transmitting / receiving unit

42

Transfer parameter determining unit

43

Storage

50

GNSS module

60

acquisition unit

61

Current speed

62

direction

70/71

Street

Claims (16)

Communication device ( 40 ), in particular (mobile) terminal, comprising: - at least one position determination unit ( 50 ) for determining position data (PosData) of the communication device; At least one radio transceiver unit ( 41 ) for communication with at least one first ( 10 ) and at least one second ( 20 ) Base station; At least one transfer parameter determination unit ( 42 ) for determining transfer parameters, characterized in that the transfer parameter determination unit ( 42 ) for determining the transfer parameters, the position data (PosData) transmitted to one of the base stations and / or the transfer parameters in a memory on the basis of the position data (PosData) identified, the position data (PosData) are associated with road data (StrData). Communication device according to claim 1, characterized by a detection unit for detection ( 60 ) of travel speed data ( 61 ) and / or travel direction data ( 62 ) of the communication device, wherein these data are taken into account in the determination of the transfer parameters. Communication device according to claim 1 or 2, characterized in that the transfer parameter determination unit ( 42 ) when determining the transfer parameters - data relating to a road course and / or - data relating to the radio wave propagation of at least one of the base stations and / or - data relating to a, a street on which the communication device is located, the maximum speed and / or - data relating to a Considered on the street on which the communication device is located. Communication device according to one of the preceding claims, characterized in that the transfer parameters are the triggering time interval, in particular at least one TTT value, and / or radio-quality data, in particular at least one HOM value. Communication device according to one of the preceding claims, characterized by a measuring unit for measuring quality data of a communication with the first base station and / or at least one signal of the first base station, wherein the communication device initiates a change of a primary communication from the first to the second base station, if the quality data, preferably via a / the tripping time interval, a / the radio quality indication according to the transfer parameters. A system comprising: - at least two base stations ( 10 ; 20 ), the at least two radio cells ( 11 ; 21 ) and for radio communication with at least one communication device ( 40 ), in particular according to one of the preceding claims, are formed; - At least one receiving unit for receiving position data (PosData) of the communication device; - At least one memory unit for storing a plurality of transfer parameters in response to position data, wherein the system is adapted to select for the at least one communication device transfer parameters based on the position data (PosData). System according to claim 6, characterized in that the system when selecting the transfer parameters - data relating to a road course and / or - data relating to the radio wave propagation of at least one of the base stations and / or - data with respect to a, a street on which the communication device is located assigned Maximum speed and / or data relating to an average speed associated with a road on which the communication device is located. System according to one of claims 6 or 7, in particular according to claim 7, characterized in that at least one base station has a transmitting unit for transmitting transfer parameters to the at least one communication device in dependence on the position data. Vehicle ( 30 ) with a communication device ( 40 ) according to one of claims 1 to 5, wherein the position detection unit is a navigation system. Method for communication between a communication device, in particular according to one of claims 1 to 5, and at least one first ( 10 ) and a second ( 20 ), in particular to a system according to one of claims 6 to 8, comprising the steps of: a) establishing a voice and / or data connection between the communication device and the first base station ( 10 ); b) determining / receiving position data (PosData) of the communication device ( 40 ), the position data (PosData) comprising road data (StrData); c) determining / receiving transfer parameters based on the road data (StrData); d) transfer of voice / data connection to the second base station ( 20 ) taking into account the determined / determined transfer parameters. Method according to claim 10, marked by, e) acquiring / receiving the travel speed data and / or travel direction data of the communication device, wherein these data are taken into account in the determination of the transfer parameters. A method according to claim 10 or 11, characterized in that in step c) a tripping time interval for the transfer, in particular at least one TTT value, and / or radio quality information, in particular at least one HOM value, are determined / received. Method according to one of claims 10-12, in particular according to claim 12, marked by f) transmitting the TTT value and / or the HOM value from a base station to a communication device and g) Modification of the TTT value and / or the HOM value of the communication device. Method according to one of Claims 10-13, in particular according to Claim 13, characterized by h) storing a modified TTT value and / or a modified HOM value together with transfer qualities which determine the quality of the transfer from the first ( 10 ) to the second base station ( 20 ) specify. Method according to one of claims 10-14, in particular according to claim 13 or 14, characterized in that the modification of a TTT value and / or a HOM value comprises an optimization, wherein a data loss rate (R _out (θ)) is minimized for a given number of ping-pong handovers (R _pp (θ)) , Method according to one of claims 10-15, marked by, i) quality measurement with regard to the performed transfer of the communication device into a second radio cell of a second base station based on a modified TTT value and / or a modified HOM value; j) Comparison of the measured handover quality with stored handover qualities to optimize future handovers.

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