FR3126834A1 - Dynamic allocation of frequencies associated with local licenses - Google Patents

Abstract

Dynamic allocation of frequencies associated with local licenses Method taking into account the deployment of radio base stations, to allocate or reallocate the frequencies associated with local licenses. This process is based on estimating the interference between two deployments associated with two local licenses. Figure for abstract: [Fig. 7]

Description

Dynamic allocation of frequencies associated with local licenses

Description of figures

There shows an example of a local license on a shared frequency band in accordance with the state of the art.

There describes the procedure for allocating frequencies associated with local licenses in accordance with the state of the art.

There shows an example of radio base station deployment by an operator with local licenses.

There shows an example of radio base station deployment by a second operator with local licenses.

There shows an example of radio base station deployment by a third operator with local licenses.

There shows an example of frequency preferences associated with local licenses.

There shows the procedure for allocating frequencies associated with local licenses in accordance with the present invention.

There shows an alternative procedure for allocating frequencies associated with local licenses in accordance with the present invention.

There describes the procedure for calculating the interference cost of a so-called “impacting” local license on a so-called “impacted” local license.

There shows an example of calculating the deployment interference cost associated with a local license on the deployment associated with another local license.

There shows a second example of calculating the interference cost of the deployment associated with a local license on the deployment associated with another local license.

There shows a third example of calculating the interference cost of a licensed area on another licensed area.

There illustrates the calculation of the total interference cost applied to allocation map 1 of [Table 2].

There illustrates the calculation of the total interference cost applied to allocation map 2 of [Table 2].

State of the art on dynamic spectrum sharing

There shows an example of a local license on a shared frequency band in accordance with the state of the art.

A local license is associated with a frequency range and an administrative area. This frequency range is not necessarily the same throughout the life of a local licence. The procedure for selecting the frequency range associated with a local license is described in .

In the case of CBRS (“Citizens Broadband Radio Service”), a local license (called “PAL”, or “Priority Access License”), is associated with a county, and the frequency range of each license is 10 MHz .

CBRS is a service defined by the FCC regulatory authority (“Federal Communications Commission”, document 15-47) allowing the sharing of frequencies on the 3.5 GHz frequency band between three priority levels, or 3 tiers:

Primary users (or priority users),

PAL (Priority Access Licensees) secondary users,

Third-party users GAA (“General Authorized Access”).

The Wireless Innovation Forum defines the architecture and protocols of the CBRS service, in accordance with FCC requirements.

The holder of a local license (the "Priority Access Licensee" in the case of CBRS) is entitled to deploy radio base stations in the county associated with this license.

Once these radio base stations are deployed, the licensee is authorized to create a protection zone around these radio base stations.

In the case of CBRS, the contour of this protection area (known as "PPA" or "PAL Protection Area") is calculated by the SAS server (or "Spectrum Access System", or spectrum access controller) to which are connected radio base stations) depending on the radio coverage of each radio base station deployed, up to a reception threshold of -96 dBm / 10 MHz.

Several disjoint protection zones can be created in the same county.

In addition, the outline of a protection zone may extend over several counties.

The method for creating a PPA is described in requirement R2-PAL-02 of document WINNF-TS-0112.

At each point of a protection zone, the licensee, i.e. the operator to whom one or more local licenses are assigned, is protected from interference generated by radio base stations deployed nearby by other licensees. , up to a predefined protection threshold.

In the case of CBRS, this protection threshold is -80 dBm / 10 MHz.

State of the art on the allocation of frequencies associated with local licenses

There describes the procedure for allocating frequencies associated with local licenses in accordance with the state of the art.

This procedure is executed, for example by the SAS server, at the end of the acquisition of local licenses (for example following an auction of local licenses), and aims to select the frequencies best satisfying the preferences provided by each license holder.

In step 1, each licensee provides, for each county for which it has one or more licenses, its frequency preferences.

These preferences can for example consist of indicating, for each 10 MHz channel, one of the following 3 alternatives:

- This channel is preferred by the licensee,

- This channel is acceptable to the licensee,

- This channel should be avoided.

Furthermore, in the event that the licensee has licenses in contiguous counties, the licensee may indicate whether it wishes the frequencies obtained at the end of this allocation procedure to be identical in these counties.

For a given county, several licensees may have local licenses.

In the case of CBRS, each county is associated with a maximum of 7 local licenses.

A licensee cannot have more than 4 licenses for a given county.

Stage 2 of the consists in filtering, for each county, the possible frequency allocations, and retaining those which best satisfy the preferences of each license holder in this county.

This step may consist of giving a score to each possible frequency allocation in a given county, then selecting the allocations whose score exceeds a predefined threshold, or even selecting the N allocations whose score is the highest, N being predefined .

The higher the number of selected allocations, the more complex step 3 will be.

This score can be calculated as follows:

For each local license in the county, the score is incremented by the value "-1" in the case where the licensee's preference for the frequency assigned to this local license is "to be avoided", by the value "0" in the case where this preference is “acceptable”, and of the value “1” in the case where this preference is “preferred”.

In the interests of fairness, certain frequency allocations may be excluded even if the score obtained is high, for example in the event that one of the county licensees does not obtain any desired frequency.

An example of frequency allocations retained at the end of this step 2 is detailed in [Table 1] above.

When an operator has local licenses in neighboring counties, he can indicate whether he wishes the frequencies allocated to these local licenses at the end of the procedure described in be the same.

Stage 3 of the consists in identifying, among all the frequency allocations obtained at the end of stage 2, the "allocation maps" that best satisfy the geographical contiguity preferences provided by the licensees.

On a large territory, for example the United States, this step can be carried out on geographical areas smaller than the entire territory. A geographical area can for example be a “CMA” or “cellular market area” as defined by the FCC in the United States.

An “allocation map” for a given geographical area is the list of frequency allocations of all local licenses belonging to this geographical area.

An example of possible "allocation maps" retained at the end of this step 3 is detailed in [Table 2].

Deployment example

There shows an example of radio base station deployment by an operator with local licenses.

In the remainder of the invention, the county is taken as an example of an administrative area associated with a local license.

In this example, operator A holds a license, identifier "PAL_C1_OpA", associated with county C1, and a license identifier "PAL_C2_OpA" associated with county C2.

On the zone associated with the local license "PAL_C1_OpA", operator A has created a protection zone Z1_C1_OpA, in which two radio base stations are deployed.

On the zone associated with the local license "PAL_C2_OpA", operator A has created a protection zone Z2_C2_OpA, in which a radio base station is deployed.

There shows a second example of radio base station deployment by an operator with local licenses.

In this example, operator B has an identifier license "PAL_C1_OpB" associated with county C1, and an identifier license "PAL_C2_OpB" associated with county C2.

There shows a third example of radio base station deployment by an operator with local licenses.

In this example, operator C holds an identifier license "PAL_C4_OpC" associated with county C4, and an identifier license "PAL_C3_OpC" associated with county C3.

There shows an example of frequency preferences associated with the local licenses of operators A, B and C described in , , And .

These frequency preferences are used during the frequency allocation procedure, as described in the .

It is assumed that 4 frequencies are available, from F1 to F4.

The county C1 table shows for example that operator A, who has a local license in this county, has indicated that F1 and F2 are his preferred frequencies, that F3 is an acceptable frequency, and that F4 is a frequency at avoid.

[Table 1] shows, for each county, the list of frequency allocations obtained at the end of step 2 of the , taking as input parameters the frequency preferences described in .

For example, for county C1, the two allocations with the highest score according to the calculation described in are the following :

1) Either frequency F1 is assigned to the local license PAL_C1_OpA and frequency F2 is assigned to the local license PAL_C1_OpB.

2) Either the frequency F2 is allocated to the local license PAL_C1_OpA and the frequency F1 is allocated to the local license PAL_C1_OpB.

Similarly, for county C2, the two allocations with the highest score according to the calculation described in are the following :

1) Either frequency F1 is assigned to the local license PAL_C2_OpA and frequency F2 is assigned to the local license PAL_C2_OpB.

2) Or the frequency F2 is allocated to the local license PAL_C2_OpA and the frequency F1 is allocated to the local license PAL_C2_OpB.

The [Table 2] above shows the list of "allocation maps" obtained at the end of the execution of step 3 of the , i.e. the list of "allocation maps" best satisfying the geographic contiguity criterion, among all the "allocation maps" obtained at the end of step 2 of the .

It is assumed in this example that operators A, B, C all three want the criterion of geographical contiguity to be satisfied for their respective local licenses.

In this example, two allocation maps best satisfy the geographic contiguity criterion.

These two “allocation maps” are equivalent from the point of view of the frequency preferences illustrated in . Therefore, the SAS server can arbitrarily choose to allocate frequencies to local licenses according to allocation map 1 or allocation map 2 described in [Table 2].

Conversely, for example, an allocation map which would attribute the frequency F2 to the "PAL_C4_OpC" license could not satisfy the criterion of geographical contiguity for operator C since the only allocation retained at the end of stage 2 of the for the local license "PAL_C3_OpC" on the neighboring county C3, is the frequency F1, as illustrated in [Table 1].

description of the problem

The frequency allocation procedure described in does not take into account the deployment of licensees' radio base stations.

Depending on the deployment of the licensees' radio base stations, the frequency allocations obtained following the procedure described in may prove unsatisfactory, or even unusable, for licensees.

In particular, in the event that two operators, each holding a local license in neighboring counties, create protection zones near the border between these two counties, the authorized transmission power of the radio base stations in each zone protection will be likely to be reduced by the SAS server, in order to guarantee that at any point of each protection zone, the authorized interference threshold, guaranteed for each local license, is not exceeded.

In addition, the deployment of radio base stations on a given local license is likely to evolve during the life of a local license.

It follows that a frequency allocation initially satisfactory for operators is likely to deteriorate over time.

The present invention responds to this limitation by introducing a procedure for allocating or re-allocating frequencies associated with local licenses taking into account the deployment of licensees. This procedure is based on a method for estimating the interference between two deployments associated with two local licenses, as described in more detail later in the invention.

1. Indication, par le détenteur d’une ou plusieurs licences locales, au contrôleur d’accès au spectre :
   1. des préférences de fréquences pour ces licences locales,
   2. des préférences de contiguïté géographique, indiquant les licences locales de zones administratives voisines et associées au même licencié pour lesquelles la fréquence allouée à l’issue de cette procédure doit, de préférence, être la même.
2. pour chaque zone administrative, identification des allocations de fréquences satisfaisant au mieux aux préférences de fréquences des licences locales associées à cette zone administrative.
3. identification des cartes d’allocation satisfaisant au mieux les préférences de contiguïté géographique fournies par les licenciés à l’étape i, une carte d’allocation, sur une zone géographique donnée, étant constituée de la liste des fréquences allouées à chacune des licences locales appartenant à cette zone géographique.
4. Pour chaque paire de deux licences locales associées à des zones administratives voisines et détenues par des licenciés différents, estimation du coût d’interférence causé par le déploiement de stations de base radio de la première licence locale, dite licence impactante, sur le déploiement de la seconde licence locale, dite licence impactée, et vice versa.
5. sélection de la carte d’allocation pour laquelle le coût total d’interférence est le plus bas, ce coût total d’interférence étant constitué, pour une carte d’allocation donnée, de la somme des côuts d’interférence calculés à l’étape iv et applicables pour cette carte d’allocation, un coût d’interférence étant dit applicable si la licence impactante et la licence impactée sont sur la même fréquence.

The method according to the invention, taking into account the deployment of the radio base stations, for allocating or reallocating the frequencies associated with local licenses, each local license authorizing the licensee to create protection zones around the deployed radio base stations, characterized by the following operations and considering that each local license is associated with an administrative area, that these operations are carried out by a spectrum access controller in a given geographical area, and that a geographical area consists of a contiguous set of administrative areas:

1. Indication, by the holder of one or more local licenses, to the spectrum access controller:
   1. frequency preferences for these local licenses,
   2. geographical contiguity preferences, indicating the local licenses of neighboring administrative areas and associated with the same licensee for which the frequency allocated at the end of this procedure should preferably be the same.
2. for each administrative area, identification of the frequency allocations that best satisfy the frequency preferences of the local licenses associated with this administrative area.
3. identification of the allocation maps best satisfying the geographical contiguity preferences provided by the licensees in step i, an allocation map, over a given geographical area, consisting of the list of frequencies allocated to each of the local licenses belonging to this geographic area.
4. For each pair of two local licenses associated with neighboring administrative areas and held by different licensees, estimate of the cost of interference caused by the deployment of radio base stations of the first local license, called the impacting license, on the deployment of the second local license, called impacted license, and vice versa.
5. selection of the allocation map for which the total interference cost is the lowest, this total interference cost consisting, for a given allocation map, of the sum of the interference costs calculated in step iv and applicable for this allocation card, an interference cost being said to be applicable if the impacting license and the impacted license are on the same frequency.

The method according to the invention, characterized in that the estimation of said interference cost of an impacting local license on an impacted local license consists in summing the interference cost of each radio base station of the deployment associated with the impacting license on the impacted local license.

The method according to the invention, characterized in that said interference cost of a radio base station (BS), is the sum of the interference value (I(BS, P)) caused by this base station at each point (P) of each protection zone associated with the impacted license.

The method according to the invention, characterized in that said interference value (I(BS, P)) takes the value 0 in the case where the interference estimated at the point P is lower than a predefined threshold, and the value 1 otherwise.

The method according to the invention, characterized in that said interference value (I(BS, P)) takes the value 0 in the case where the estimated interference at point P is less than a predefined threshold, and the value of the difference between the estimated interference and this predefined threshold in the opposite case.

Description of the invention

There shows the procedure for allocating frequencies associated with local licenses in accordance with the present invention.

Stage 2 of the is identical to step 2 of the state of the art described in , and consists of filtering frequency allocations according to frequency preferences.

Stage 3 of the is similar to step 3 of the and consists of filtering the allocation maps according to geographical contiguity preferences, over a given geographical area.

At step 4 of the , the SAS server estimates the cost of interference between deployments in neighboring counties, except in the case where the holder of the local licenses associated with each of these deployments is the same.

In the deployment example described in the figures , And , this step 4 consists in calculating:

– The interference cost of the radio base stations located in the zone Z1_C1_OpA (associated with the local license PAL_C1_OpA) on the zone Z2_C2_OpB (associated with the local license PAL_C2_OpB).

– The interference cost of the radio base stations located in the Z1_C1_OpB area on the Z2_C2_OpA area.

– The interference cost of the radio base stations located in the Z2_C2_OpB area on the Z1_C4_OpC area.

– The interference cost of the radio base stations located in the Z2_C2_OpB zone on the Z2_C3_OpC and Z3_C3_OpC zones.

– The interference cost of the radio base stations located in the Z1_C4_OpC zone on the Z2_C2_OpB zone.

– The interference cost of the radio base stations located in the Z2_C3_OpC and Z3_C3_OpC zones on the Z2_C2_OpB zone.

The interference cost is a unitless value, obtained from the estimation of the radio interference caused by each radio base station of a so-called “impacting” local license on a so-called “impacted” local license.

The calculation of this interference cost is described in more detail in the remainder of the invention.

The [Table 3] above shows the interference cost obtained after executing step 4 of the on the deployment described in , And .

For example, the deployment interference cost associated with the PAL_C2_OpA license on the protection zones associated with the PAL_C4_OpC local license is 120.

Selecting the allocation map with the lowest total interference cost

At step 5 of the , the SAS server selects the allocation map with the lowest total interference cost among all possible allocation maps identified in step 3.

The total total interference cost is the sum of all interference costs associated with a given allocation map.

It is assumed for example that the allocation maps identified at the end of step 3 of the are the two allocation maps described in [Table 2]

There illustrates the calculation of the total interference cost applied to allocation map 1 of [Table 2].

In this allocation map, the only local licenses that impact deployments of different operators in neighboring counties are:

– the license of operator C on account C4 (PAL_C4_OpC)

– the license of operator C on account C3 (PAL_C3_OpC)

– the license of operator A on account C2 (PAL_C2_OpA)

The interference cost between each neighboring local license is indicated on the arrows and corresponds to the interference cost values described in [Table 3].

The total interference cost for allocation 1 is therefore 120 + 50 + 0 + 10 = 180.

There illustrates the calculation of the total interference cost applied to allocation map 2 of [Table 2].

In this allocation map, the only local licenses that impact deployments of different operators in neighboring counties are:

– the license of operator C on account C4 (PAL_C4_OpC)

– the license of operator C on account C3 (PAL_C3_OpC)

– the license of operator B on account C2 (PAL_C2_OpB)

The total interference cost for allocation map 2 is therefore 150 + 200 + 0 + 0 = 350.

At the end of step 5, the allocation map selected in this example is therefore allocation map 1, whose total interference cost is 180.

Calculation of interference cost according to the present invention

There describes the procedure for calculating the interference cost of a so-called “impacting” local license on a so-called “impacted” local license.

In step 1, the interference cost is initialized to zero.

In step 2, the SAS server adds the interference cost of each radio base station associated with the impacting local license to the impacted local license.

The calculation of the interference cost of a radio base station carried out in step 2 consists of summing the interference value ( I(BS, P) ) caused by this base station at each point (P ) of each protection zone associated with the impacted license (for example by taking a point every 80 meters inside each protection zone).

There shows an example of calculating the deployment interference cost associated with a local license on the deployment associated with another local license.

In this example, it is assumed that operator A has a local license associated with county 1 (PAL_C1_OpA).

This local license authorizes Operator A to deploy radio base stations in County A, as well as to create protection zones associated with these radio base stations.

In this example, operator A has created two protection zones Z1 and Z2 associated respectively with radio base stations BS1 and BS2.

It is assumed that operator B has a local license associated with county 2 (PAL_C2_OpB).

In this example, operator B has created a protection zone Z3 associated with radio base stations C3 and C4.

In accordance with the procedure described in , the calculation of the interference cost of the deployment associated with the local license PAL_C1_OpA on the deployment associated with the local license PAL_C2_OpB consists of:

1) identify the radio base stations of the impacting deployment. In this example, there are two radio base stations (BS1 and BS2).

2) identify the protection zones of the impacted deployment. In this example, there is a protection zone (Z3).

3) for each radio base station BS identified in 1), and for each point P of the protection zone Z3, evaluate the interference value I(BS, P) .

It is assumed in this example that the interference value I(BS, P) returns the value 0 in the case where the estimated interference of the radio base station BS at point P is less than a predefined threshold, and the value 1 otherwise.

The calculation of the interference can be performed using a radio propagation algorithm, taking into account the parameters of the radio base station having an impact on the radio propagation such as:

- latitude,

– the length,

- the height,

– the antenna parameters associated with the radio base station (e.g. azimuth and beamwidth),

– the radiation diagram,

– the authorized transmission power.

The right part of the shows, for each impacting radio base station, the points of the Z3 protection zone where the interference is greater than the predefined threshold. Each of these points is illustrated by a gray square.

In this example, the function I(BS, P) returned the value 1 in 5 points for the radio base station BS1 and in 4 points for the radio base station BS2.

The interference cost of the deployment associated with the local license PAL_C1_OpA on the deployment associated with the local license PAL_C2_OpB is therefore 5 + 4 = 9.

There shows a second example of calculating the interference cost of the deployment associated with a local license on the deployment associated with another local license.

In this example, operator B has created a Z3 protection zone associated with the radio base station BS3 and a Z4 protection zone associated with the radio base station BS4.

In accordance with the procedure described in , the calculation of the interference cost of the deployment associated with the local license PAL_C1_OpA on the deployment associated with the local license PAL_C2_OpB consists of:

1) identify the radio base stations of the impacting deployment. In this example, there are two radio base stations (BS1 and BS2).

2) identify the protection zones of the impacted deployment. In this example, there are two protection zones (Z3 and Z4).

3) for each radio base station BS identified in 1), and for each point P of the protection zone Z3, evaluate the interference value I(BS, P) .

The right part of the shows, for each impacting radio base station, the points of the protection zones Z3 and Z4 where the interference is greater than the predefined threshold.

In this example, the function I(BS, P) returned the value 1 at no point for radio base station BS1 and at 1 point for radio base station BS2.

The interference cost of the deployment associated with the local license PAL_C1_OpA on the deployment associated with the local license PAL_C2_OpB is therefore 1.

Alternative Calculation of Interference Cost

Alternatively, the function I(BS, P) returns the value 0 in the event that the estimated interference from the radio base station BS at point P is less than a predefined interference threshold, and the difference between the estimated interference and this predefined threshold otherwise.

There shows an example of calculating the interference cost according to this alternative. The squares colored in white indicate the points for which the function I(BS, P) returned the value 0. The squares colored in shades of gray indicate the points for which the function I(BS, P) returned the difference between l estimated interference and a predefined interference threshold.

The gradation of gray illustrates the value of the local interference obtained at each point, going from lightest to darkest.

Alternative to the frequency allocation procedure described in

There shows an alternative procedure for allocating frequencies associated with local licenses in accordance with the present invention.

In this alternative, the selection of the allocations according to the interference cost (in step 4) is carried out before the selection according to the criterion of geographical contiguity (in step 5).

Step 4 may consist, for example, in selecting the allocation maps having a total interference cost below a predefined threshold, or even in selecting the N allocation maps whose total interference cost is the lowest, N being predefined.

Claims (6)

A method taking into account the deployment of radio base stations, for allocating or reallocating the frequencies associated with local licenses, each local license authorizing the licensee to create protection zones around the deployed radio base stations, characterized by the following operations and considering that each local license is associated with an administrative area, that these operations are carried out by a spectrum access controller in a given geographical area, and that a geographical area consists of a contiguous set of administrative areas:

1. Indication, by the holder of one or more local licenses, to the spectrum access controller:
   1. frequency preferences for these local licenses,
   2. geographical contiguity preferences, indicating the local licenses of neighboring administrative areas and associated with the same licensee for which the frequency allocated at the end of this procedure should preferably be the same.
2. for each administrative area, identification of the frequency allocations that best satisfy the frequency preferences of the local licenses associated with this administrative area, this step being able for example to consist in giving a score to each possible frequency allocation, then in selecting the allocations whose score exceeds a predefined threshold, or to select the N allocations whose score is the highest, N being predefined.
3. identification of the allocation maps best satisfying the geographic contiguity preferences provided by the licensees in step i, this identification possibly consisting, for example, of selecting the allocation maps for which the criterion of geographic contiguity is satisfied for the largest number of local licenses, an allocation map, for a given geographical area, consisting of the list of frequencies allocated to each of the local licenses belonging to this geographical area.
4. For each pair of two local licenses associated with neighboring administrative areas and held by different licensees, estimate of the cost of interference caused by the deployment of radio base stations of the first local license, called the impacting license, on the deployment of the second local license, called impacted license, and vice versa.
5. selection of the allocation map for which the total interference cost is the lowest, this total interference cost consisting, for a given allocation map, of the sum of the interference costs calculated in step iv and applicable for this allocation card, an interference cost being said to be applicable if the impacting license and the impacted license are on the same frequency.

Method according to claim, characterized in that the estimation of said interference cost of a local license impacting on an impacted local license consists in summing the interference cost of each radio base station of the deployment associated with the license impacting on the impacted local license. Method according to claim 2, characterized in that said interference cost of a radio base station (BS), is the sum of the interference value (I(BS, P)) caused by this base station in each point (P) of each protection zone associated with the impacted license. Method according to Claim 3, characterized in that the said interference value (I(BS, P)) takes the value 0 in the case where the interference estimated at the point P is lower than a predefined threshold, and the value 1 in the opposite case. Method according to Claim 3, characterized in that the said interference value (I(BS, P)) takes the value 0 in the case where the interference estimated at the point P is lower than a predefined threshold, and the value of the difference between the estimated interference and this predefined threshold otherwise. Process according to Claims 1 to 5, characterized in that stages iv and v of Claim 1 are carried out before stage iii.