CN101720096B - Self-configuration method of physical district ID in LTE cellular network - Google Patents

Abstract

The invention discloses a self-configuration method of a physical district ID in a LTE cellular network, mainly solving the problem of contradiction between limited number of PCIs and large number of wireless districts in a LTE system. In the self-configuration method, a base station divides a distribution area into closely connected square virtual districts according to network scale; a local unique virtual district address is allocated to each virtual district according to a spatial multiplexing principle; the base station acquires the located virtual district address through mapping according to self geographical position and takes the address as an identification section in a PCI cluster; an OAM confirms a used address collection and initializes a standby address collection; conflict resolution is carried out in cellular districts with conflict occurrences; identification sections in the PCI cluster are configured to newly introduced cellular districts; the OAM updates the standby address collection in real time according to a report from the base station; and the OAM completes allocation of the identification sections among PCI clusters. The invention effectively alleviates the contradiction between the limited number of PCIs and the large number of wireless districts, can better adapt to the trend of coexistence of various base stations in a future heterogeneous network, and is convenient for network dilatancy.

Description

The self-configuration method of physical district ID in the LTE Cellular Networks

Technical field

The present invention relates to wireless communication field, particularly relate to 3G (Third Generation) Moblie Long Term Evolution 3GPP LTE system, propose a kind of distributed method that disposes automatically based on the physical district ID of base station eNB geographical location information specifically.

Background technology

In the 3G (Third Generation) Moblie long evolving system, support 504 physical district IDs, so the multiplexing of physical district ID is inevitable in different cellular cells.In 3GPP technical specification TS 36.902V1.0.1, the distribution of clear and definite physical district ID should be followed following two criterions:

Do not have conflict, promptly a wireless area can not use the physical district ID identical with its neighbor cell;

Nothing is obscured, and promptly a wireless area can not have the neighbor cell that uses same physical sub-district ID.

Mentioned above principle can reduce within the double bounce, and the physical district ID of cellular cell is reusable not, can be multiplexing outside the double bounce scope.But for reducing the interference between cellular cell, the multiplexing minizone that need make physical district ID as much as possible is apart from maximum.

When a panel region is introduced new base station eNB, need select a physical district ID effectively for each wireless area that this base station is supported, and avoid physical district ID with neighbor cell to clash or obscure.As shown in Figure 1, C is the new base station eNB of introducing, and need be sub-district C1 and C2 configures physical sub-district, sub-district ID, and can not clash or obscure with physical district ID with existing.

Existing collocation strategy about physical district ID mainly is divided into two types: centralized configuration strategy and decentralized configuration strategy.Confirmed the framework of two kinds of collocation strategies, framework is described below:

(1) operation and maintenance OAM should provide an effective physical district ID tabulation or a definite physical district ID value, and the base station can therefrom be chosen.

(2) physical district ID should be selected based on centralized or distributed method in the base station:

1) centralized physical district ID allocative decision: OAM sends specific physical district ID value to the base station, as the physical district ID value of this base station cell.

2) distributed physical district ID allocative decision: OAM is to the tabulation of a physical district ID of base station transmission, and the base station is therefrom selected a physical district ID randomly.

In sensor network research; The field, contain people such as quick, Li Jiandong and propose a kind of new sensor network MAC address assignment algorithm; This algorithm only needs characteristic unique in subrange to the bigger problem of sensor network MAC address overhead according to MAC Address, and the method that adopts the geographical position mapping is to the MAC Address spatial reuse; Reduced the MAC Address length of node effectively, the life cycle that has prolonged sensor node.It is similar that MAC Address only needs not have the aliasing free requirement that conflict in characteristic unique in subrange and the physical district ID assigning process, so can use for reference this algorithm, is used for the self-configuring of LTE cellular network physical district ID.

In traditional cellular communication system, the configuration of physical district ID is to carry out with the mode of the network planning.Along with increasing of cellular cell number, the contradiction between the finiteness of physical district ID number and the huge number of cells seems more outstanding.In addition, traditional mode can't be upgraded to adapt in following heterogeneous network macro cell base station, picocell base station and femto cell base station and to deposit this trend.

Summary of the invention

The present invention is directed to the problem of network upgrade difficulty in finiteness and the contradiction between the huge number of cells and the traditional planning mode of physical district ID number; The self-configuration method of physical district ID in a kind of LTE Cellular Networks is proposed; Make full use of the spatial reuse of physical district ID; The wireless area of new introducing there are not conflict, the configuration of aliasing free physical district ID, with the trend that adapts to polytype base station in the following heterogeneous network and deposit.

The objective of the invention is to realize like this:

One. the definition that the present invention relates to is following:

Multiplexing sub-district is meant the virtual subdistrict that the address is identical;

Multiplex distance d _r, be meant the distance between adjacent multiplexing center of housing estate;

Address size b is meant the bit number that address field is shared;

Address space Ω is meant | Ω | and=2 ^b, wherein element is 0～(2 ^b-1);

Virtual subdistrict address set A _Cell, be meant the set of virtual subdistrict address;

Virtual subdistrict bunch is meant and uses A _CellIn whole unit of constituting of the cluster virtual subdistrict of addresses;

The base station has been used address set A _ENB, be meant the set of all already used addresses, base station in the same cell cluster;

Standby address collection A _Spare, be meant A _Spare=Ω-A _ENB

| x| is meant the gesture of gathering x, the number of element among the expression set x.

Two. technical scheme

The present invention is according to network size and spatial multiplexing principle, and physical district ID is divided in the virtual subdistrict bunch bunch identification section two parts between identification section and virtual subdistrict bunch bunch, is configured respectively:

A. bunch the configuration step of identification section in

(A1) base station is the square virtual subdistrict of close proximity with the base station distribution area dividing through making up virtual grid;

(A2) according to the principle of reusable not of virtual subdistrict address in the double bounce scope, confirm multiplex distance d _rWith address space Ω, distribute the unique numbering in part as the virtual subdistrict address for each virtual subdistrict according to the principle of space division multiplexing;

(A3) according to the position coordinates of base station, mapping obtains the virtual subdistrict under this base station, under conflict free prerequisite, with the virtual subdistrict address as the physical district ID of cellular cell bunch in identification section;

(A4) each base station to OAM report oneself use the virtual subdistrict address, OAM is according to the definite address set A of having used of these report informations _ENB, from address space Ω, remove and used the address set A _ENB, obtain initial standby address collection A _Spare

(A5) when detecting the physical district ID conflict; Change the base station of physical district ID and send the standby address collection to the OAM request; OAM sends the standby address collection to this base station; This base station is adopted the mode of selecting at random to concentrate from standby address and is chosen a new virtual subdistrict address, as identification section in the physical district ID bunch, and reports to OAM; OAM upgrades the standby address collection;

B. bunch the configuration step of identification section between

In step (A2) afterwards, OAM bunch is that unit divides with the base station distribution zone with virtual subdistrict, and OAM be each virtual subdistrict bunch numbering of distribution, as each physical district ID in the virtual subdistrict bunch bunch between identification section; Between bunch the length of identification section for the physical district ID total length deduct bunch in the length of identification section.

For a cellular cell of new introducing bunch in the configuration of identification section be from step (A3) beginning, by the end of step (A5).

If standby address is used up in certain virtual subdistrict bunch; Continue to introduce new radio honeycomb sub-district; Only need be according to new network size; In this virtual subdistrict bunch, rerun the inventive method, increase the length of identification section in the physical district ID in this virtual subdistrict bunch bunch, dispose new physical district ID bunch in identification section; By OAM be this virtual subdistrict bunch configuration new bunch between identification section.

Described standby address collection A _SpareUpdate mechanism be described below: if decompose for conflict the base station or the new cellular cell of introducing is concentrated to select for use from standby address and consumed a virtual subdistrict address, the base station reports that to OAM OAM concentrates deletion with this address from standby address; If certain virtual subdistrict address that use the base station is released, the base station reports that to OAM OAM adds this address to the standby address collection.

Described self-configuration method; Physical district ID is divided in the virtual subdistrict bunch bunch identification section two parts between identification section and virtual subdistrict bunch bunch; Be configured respectively: identification section is by base station configuration in bunch, and identification section is confirmed by OAM between bunch, realizes the distributed and centralized framework that combines.

Described self-configuration method, the starting point of design are applicable to the scene of a corresponding radio honeycomb sub-district, a base station; Support the scene of a plurality of radio honeycombs sub-district for a base station, can remaining wireless area be regarded as the wireless area of new introducing, thereby still be suitable for.

The present invention has following advantage:

1) the present invention is owing to adopt the mapping based on base station geographic position information; Can make full use of the spatial reuse of physical district ID; Effectively reduce the possibility that the macrocell physical district ID clashes and obscures, alleviate the finiteness and the huge contradiction of number of radio cells of physical district ID number;

2) the present invention is owing to introduce the notion of virtual subdistrict bunch, and the configuration of identification section can increase the distance between the cellular cell that uses same physical sub-district ID between physical district ID bunch, disturbs thereby reduce;

3) the present invention is owing to adopt the method for spatial reuse; The physical district ID number that is used for macrocell is less; Thereby can relatively large physical district ID headspace be provided for non-macrocell; Can reduce the possibility of picocell, Femto cell generation physical district ID conflict, the trend that adapts to polytype base station in following heterogeneous network better and deposit;

4) the present invention has simplified the process of physical district ID gravity treatment when clashing owing to used the mechanism of standby address collection and standby address collection real-time update, has improved gravity treatment efficient;

5) counter-measure taked of the situation used up for standby address in certain virtual subdistrict bunch of the present invention; Only to bunch generation effect of this virtual subdistrict; Therefore generally; Can the configuration of physical district ID in the peripheral cell bunch not exerted an influence, thereby can avoid the situation of " pulling one hair and move the whole body " to take place, be convenient to the dilatation of network.

Description of drawings

Fig. 1 is the existing use-case sketch map that the present invention uses;

Fig. 2 is the configuration flow figure of physical district ID among the present invention;

Fig. 3 is virtual subdistrict and the virtual subdistrict bunch sketch map of dividing in the layoutprocedure of the present invention;

Fig. 4 is the spatial reuse sketch map of address in the layoutprocedure of the present invention;

Embodiment

With reference to Fig. 2, practical implementation step of the present invention is following:

One, bunch the configuration step of identification section in

Step 1, the base station is the square virtual subdistrict of close proximity with the base station distribution area dividing through making up virtual grid.

Because the base station will belong to the virtual subdistrict address and use as its physical district ID, so for fear of address conflict, when virtual subdistrict is divided, should satisfy: on average only comprise a base station in each virtual subdistrict, the division of virtual subdistrict is as shown in Figure 3.Among Fig. 3, the solid line regular hexagon is represented cellular cell, and the base station is positioned at the cellular cell center, and dashed square is represented virtual subdistrict.

In that N the equally distributed area in base station arranged is S _FieldThe zone in, the mean base station in the single virtual sub-district is counted n and is only depended on distributed areas S _FieldIn base station density ρ and virtual subdistrict area S _Cell, promptly $n=\mathrm{\&rho;}\&CenterDot;S_{\mathrm{Cell}}=\frac{N}{S_{\mathrm{Field}}}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="H2009102192166E00041.png"\; state="\{\{state\}\}">d</figure-callout>}}^2$ In virtual subdistrict, only comprise a base station, promptly during n=1, the length of side of virtual subdistrict $d=\sqrt{\frac{S_{\mathrm{Field}}}{N}}---\left(1\right)$

Know that by (1) formula the length of side d of virtual subdistrict only depends on S _FieldAnd N, and these two parameters can be confirmed at network design phase.This means that the base station can obtain S in advance _FieldConstruct identical virtual grid with N and in the same position coordinate system, and guarantee that in theory each base station is corresponding to a virtual subdistrict.

Step 2 according to the principle of reusable not of virtual subdistrict address in the double bounce scope, is confirmed multiplex distance d _rWith address space Ω, distribute the unique numbering in part as the virtual subdistrict address according to the principle of space division multiplexing for each virtual subdistrict, the virtual subdistrict address begins to comply with left multiplexing down to upper right order assignment union space from the origin of coordinates.

Because the address of base station selected own place virtual subdistrict is as identification section in the physical district ID of cellular cell bunch, so can be converted into distribution to the virtual subdistrict address to the distribution of identification section in the physical district ID bunch.If adjacent two base station spacings are R, then the ultimate range between the double bounce base station is 2R.Concrete steps are following:

1), establishes that identification section is A in its physical district ID bunch to arbitrary base station i _i, be the center of circle, be that radius is done circle with 2R with base station i, expression double bounce scope; In order to guarantee that not having the conflict nothing obscures, all base stations in the 2R scope can not multiplexing address A _iCorresponding to virtual subdistrict, then the address of interior all virtual subdistricts of 2R scope must be different from the address of base station i virtual subdistrict of living in, the i.e. local uniqueness of virtual subdistrict address; The number of virtual subdistrict is then determined by R and d jointly in this double bounce scope.

Fig. 4 a is to be that example has provided the sight when base station i is positioned at virtual subdistrict A center with R=d, representes the 2R scope with broken circle, and shadow representation is all or part of to be positioned at the virtual subdistrict within the 2R scope of base station i, and they must use the address that is different from virtual subdistrict A.

2) confirm multiplexing sub-district, divide virtual subdistrict bunch.

Fig. 4 b has provided the situation that base station i is positioned at the virtual subdistrict center, select outside the 2R scope with the nearest virtual subdistrict of virtual subdistrict A as multiplexing sub-district, represent with gray squares.Virtual subdistrict within multiplex distance must use the address that is different from virtual subdistrict A, and they constitute a virtual subdistrict bunch with virtual subdistrict A, represent with bold box.

Shown in Fig. 4 c, under extreme case, promptly when base station i was positioned at virtual subdistrict A summit, multiplexing sub-district still was positioned at outside the 2R scope of base station i, can not clash.

3) shown in Fig. 4 d, it bunch be that unit space is multiplexing down to upper right order assignment and with virtual subdistrict that the virtual subdistrict address begins to comply with a left side from the origin of coordinates, and the heavy line square is represented virtual subdistrict bunch.

To any R and d, the multiplex distance of virtual subdistrict is:

$d_r=(\mathrm{Int}\left(2\frac{R}{d}\right)+1)d---\left(2\right)$

Wherein Int () expression rounds up, and R is the spacing of adjacent two base stations, and d is the length of side of virtual subdistrict.Each virtual subdistrict is bunch by (d _r/ d) ²Individual virtual subdistrict is formed, and needs (d altogether _r/ d) ²Individual virtual subdistrict address, the i.e. number of virtual subdistrict address in each virtual subdistrict bunch: $\left|A_{\mathrm{Cell}}\right|={\left(\frac{d_r}{d}\right)}^2---\left(3\right)$ Therefore, the bit number of each virtual subdistrict bunch address field needs is:

b＝Int(log ₂|A _cell|)(4)

Wherein Int () expression rounds up element number in the address space | Ω | and=2 ^b

Suppose all to contain in each virtual subdistrict the base station, then corresponding initial standby address collection is:

A _spare＝Ω-A _cell(5)

The standby address set will be continued to employ in the decomposition of address conflict subsequent use with the introducing of new wireless area.

According to (5) formula, log in (4) formula ₂| A _Cell| during for integer, address space | Ω |=2 ^b=| A _Cell|, so

Be that the standby address collection is an empty set.At this moment it is subsequent use to reserve that address field need increase a bit, so the virtual subdistrict address size is in the present invention:

$b=\left\{\begin{array}{cc}\mathrm{Int}\left({\log }_2\right|A_{\mathrm{cell}}\left|\right)& {\log }_2\left|A_{\mathrm{cell}}\right|\&NotElement;{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="H2009102192166E00031.png,H2009102192166E00041.png"\; state="\{\{state\}\}">N</figure-callout>}}_0\\ \mathrm{Int}\left({\log }_2\right|A_{\mathrm{cell}}\left|\right)+1& {\mathrm{<figure-callout\; id="2"\; label="log"\; filenames="H2009102192166E00041.png"\; state="\{\{state\}\}">log</figure-callout>}}_2\left|A_{\mathrm{cell}}\right|\&Element;N_0\end{array}\right.---\left(6\right)$

Wherein, N ₀Be natural manifold, wherein Int () expression rounds up.

Step 3, according to the position coordinates of base station, mapping obtains the virtual subdistrict under this base station, under conflict free prerequisite, with the virtual subdistrict address as the physical district ID of cellular cell bunch in identification section.

Conflict free prerequisite is meant in same virtual subdistrict bunch, and different cellular cells should use identification section in the different physical district ID bunch.

If the position coordinates of base station eNB (x, y).Among the present invention, the virtual subdistrict address begins to comply with left multiplexing down to upper right order assignment union space from the origin of coordinates, sets up as follows by the mapping relations of base station coordinates to the virtual subdistrict address:

$\left\{\begin{array}{c}{x}_1=\left[\mathrm{int}(x/d)\right]\mathrm{mod}a\\ {\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="H2009102192166E00041.png"\; state="\{\{state\}\}">y</figure-callout>}}_1=\left[\mathrm{int}(y/d)\right]\mathrm{mod}a\end{array}\right.---\left(7\right)$

$A_{\mathrm{addr}}=\left\{\begin{array}{cc}2x_1+{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="H2009102192166E00041.png"\; state="\{\{state\}\}">y</figure-callout>}}_1^2& x_1\&le;y_1\\ x_1^2+2{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="H2009102192166E00041.png"\; state="\{\{state\}\}">y</figure-callout>}}_1+1& x_1>y_1\end{array}\right.---\left(8\right)$

Here, a=d _r/ d, int () expression rounds downwards, and mod is complementation, A _AddrBe the virtual subdistrict address that the base station was mapped to, x ₁And y ₁Be intermediate variable.

Thus, the base station only needs position coordinates based on oneself (x y) just can directly obtain to belong to the address of virtual subdistrict through Function Mapping.Under the prerequisite of zero-address conflict, with the virtual subdistrict address as identification section in the physical district ID of wireless area bunch.

Step 4, the virtual subdistrict address is used to OAM report oneself in each base station, and OAM gathers these report informations, definite address set A of having used _ENBFrom address space Ω, remove and used the address set A _ENB, obtain initial standby address collection A _Spare

Step 5 is to the radio honeycomb sub-district that the physical district ID conflict the takes place decomposition that conflicts.

When two or more base stations fall into same virtual subdistrict, through map addresses, the several base stations that are positioned at same virtual subdistrict will obtain identical virtual subdistrict address.Tried to be the first when using by other base station when detecting the physical district ID that oneself uses; The standby address collection is sent to the OAM request in this base station; OAM sends the standby address collection to this base station; The base station is adopted the mode of selecting at random to concentrate from standby address and is chosen a new virtual subdistrict address, as identification section in the physical district ID bunch, and reports to OAM; OAM upgrades the standby address collection.

Standby address collection A _SpareRenewal, carry out as follows:

Consumed a virtual subdistrict address if the base station concentrates to select for use from standby address for the perhaps new cellular cell of introducing of conflict decomposition, the base station reports that to OAM OAM deletes this address according to report information from standby address is concentrated;

If certain virtual subdistrict address that use the base station is released, the base station reports that to OAM OAM adds this address to the standby address collection according to report information.

Two, identification section distributes between physical district ID bunch

In bunch in the identification section layoutprocedure, after step 2 is accomplished, the distribution of identification section between just can carrying out bunch.OAM bunch is that unit divides with the base station distribution zone with virtual subdistrict; Each virtual subdistrict bunch distributes a numbering by OAM; As each wireless area physical district ID in the virtual subdistrict bunch bunch between identification section, between bunch the length of identification section for the physical district ID total length deducts disposed bunch in identification section length b bit.The configuration of identification section guarantees to use the virtual subdistrict bunch distance of identification section between same cluster bigger based on the distance between the cell cluster between bunch.

For the new situation of introducing a cellular cell in the network of having runed; The configuration of identification section is carried out in the following manner in bunch: whether the virtual subdistrict address that own affiliated virtual subdistrict is at first detected in the base station is used; If be not used, then with this virtual subdistrict address as cellular cell bunch in identification section; If be used, the base station is adopted the mode of selecting at random to concentrate from standby address and is chosen a new virtual subdistrict address, as identification section in the physical district ID bunch.Report to OAM after accomplishing the configuration of identification section in the physical district ID bunch the base station; OAM upgrades the standby address collection.

For any situation that virtual subdistrict bunch standby address is used up; Continue to introduce new radio honeycomb sub-district; Only need be according to new network size; In this virtual subdistrict bunch, rerun the configuration step of identification section in described bunch, increase the length of identification section in the physical district ID in this virtual subdistrict bunch bunch, dispose new physical district ID bunch in identification section; By OAM be this virtual subdistrict bunch configuration new bunch between identification section.

Terminological interpretation

PCI:Physical Cell Identity, physical district ID;

LTE:Long Term Evolution, Long Term Evolution;

ENB:Evolved Node B, evolved Node B, i.e. base station in the LTE system;

OAM:Operation and Maintenance, operation and maintenance.

Claims (6)

1. the self-configuration method of physical district ID in the LTE Cellular Networks is characterized in that, according to network size and spatial multiplexing principle, physical district ID is divided in the virtual subdistrict bunch bunch identification section two parts between identification section and virtual subdistrict bunch bunch, is configured respectively:

A. bunch the configuration step of identification section in

(A1) base station is the square virtual subdistrict of close proximity with the base station distribution area dividing through making up virtual grid;

(A2) according to the principle of reusable not of virtual subdistrict address in the double bounce scope, confirm multiplex distance d _rWith address space Ω, distribute the unique numbering in part as the virtual subdistrict address according to the principle of space division multiplexing for each virtual subdistrict,

Described part is unique, is in the double bounce scope, and different virtual subdistricts is distributed different virtual subdistrict addresses, and this double bounce scope is meant with the cellular base stations to be the center of circle, and radius is the zone of 2R, and R is the spacing of adjacent two base stations,

Described virtual subdistrict address is to begin according to multiplexing down to the upper right order assignment row space of going forward side by side from a left side from the origin of coordinates;

(A3) according to the position coordinates of base station, mapping obtains the virtual subdistrict under this base station, under conflict free prerequisite, with the virtual subdistrict address as the physical district ID of cellular cell bunch in identification section;

(A4) each base station to OAM report oneself use the virtual subdistrict address, OAM is according to the definite address set A of having used of these report informations _ENB, from address space Ω, remove and used the address set A _ENB, obtain initial standby address collection A _Spare

(A5) when detecting the physical district ID conflict; Change the base station of physical district ID and send the standby address collection to the OAM request; OAM sends the standby address collection to this base station; This base station is adopted the mode of selecting at random to concentrate from standby address and is chosen a new virtual subdistrict address, as identification section in the physical district ID bunch, and reports to OAM; OAM upgrades the standby address collection;

B. bunch the configuration step of identification section between

In step (A2) afterwards, OAM bunch is that unit divides with the base station distribution zone with virtual subdistrict, and OAM be each virtual subdistrict bunch numbering of distribution, as each physical district ID in the virtual subdistrict bunch bunch between identification section; Between bunch the length of identification section for the physical district ID total length deduct bunch in the length of identification section.

2. self-configuration method according to claim 1, the configuration of identification section in wherein said bunch, in the network of having runed new introduce a cellular cell bunch in the configuration of identification section be from step (A3) beginning, by the end of step (A5).

3. self-configuration method according to claim 1; For any situation that virtual subdistrict bunch standby address is used up; If continue to introduce new radio honeycomb sub-district, only need be according to new network size, in this virtual subdistrict bunch, rerun the configuration step of identification section in described bunch; Increase the length of identification section in the physical district ID in this virtual subdistrict bunch bunch, dispose new physical district ID bunch in identification section; By OAM be this virtual subdistrict bunch configuration new bunch between identification section.

4. self-configuration method according to claim 1, the described conflict free prerequisite of step (A3) wherein is meant in same virtual subdistrict bunch, different cellular cells should use identification section in the different physical district ID bunch.

5. self-configuration method according to claim 1, wherein the described address set A eNB that used of step (A4) is to report the virtual subdistrict address of oneself selecting for use by each base station to OAM, is gathered definite by OAM.

6. self-configuration method according to claim 1, the wherein renewal of (A5) described standby address collection Aspare, carry out as follows:

(6A) consumed a virtual subdistrict address if the base station concentrates to select for use from standby address for the perhaps new cellular cell of introducing of conflict decomposition, the base station reports that to OAM OAM deletes this address from standby address is concentrated;

(6B) if certain virtual subdistrict address that use the base station is released, the base station reports that to OAM OAM adds this address to the standby address collection.

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