Method for implementing a cell load balancing mechanism in wireless networks

Patent metadata

Field	Value
Publication number	US-9510240-B2
Application number	US-201314417418-A
Country	US
Kind code	B2
Filing date	Jul 23, 2013
Priority date	Jul 27, 2012
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

The method comprising at least one wireless user terminal, UE, connected through a wireless network to a serving base station and a plurality of network cells, each one comprising a base station, said at least one wireless UE: estimating the cell loads of the serving base station and of the plurality of network cells by analysing a downlink air interface load; providing to said wireless network, information about the actual cell load estimation of said plurality of cells, and performing a network cell selection based on said estimated cell loads, wherein said cell selection is performed without any exchange of cell load between said plurality of network cells.

First claim

The invention claimed is:

1. A method for implementing a cell load balancing mechanism for wireless networks including a plurality of network cells, each of said plurality of network cells comprising a base station, by at least one wireless user equipment (UE) connected through a wireless network to a serving base station, the method comprising said at least one wireless UE performing actions comprising:
estimating cell loads of the serving base station and of the plurality of network cells by analyzing a downlink air interface load, wherein in case of Wideband Code Division Multiple Access (WCDMA) cells, said downlink air interface load is determined based on a maximum available TX power in the cell (MAX_TX_POWER, said MAX_TX_POWER being included as part of any relevant system information blocks transmitted in a broadcast channel or created within a new system information block;
providing, to said wireless network, information about the estimated cell load of said plurality of network cells; and
performing a network cell selection based on said estimated cell loads,
wherein said network cell selection is performed without any exchange of cell load between said plurality of network cells.

2. The method according to claim 1 , wherein said estimation of the downlink air interface load (L) is given by the following equation:

L
=

P
TX

MAX_TX
⁢
_POWER

,

wherein P TX denotes a total transmission power as derived from received powers for each of channelization codes i, P i,RX , and an estimated path loss PL through the equations:

P
TX

⁡

(
dBm
)

=

∑
i

⁢

P

i
,
RX

⁡

(
dBm
)

+

PL
⁡

(
dB
)

PL
⁡

(
dB
)

=

P

CPICH
,
TX

⁡

(
dBm
)

-

P

CPICH
,
RX

⁡

(
dBm
)

,

where P CPICH,TX denotes a transmitted power of a Common Pilot Channel (CPICH) as broadcast by the network cell, and P CPICH,RX is a received CPICH power.

3. The method according to claim 1 , further comprising estimating said downlink air interface load in a case of Long Term Evolution cells based on an averaged number of occupied resource elements in a subframe.

4. The method according to claim 3 , wherein said estimation of the downlink air interface load (L) is given by the following equation:

L
=

N

REs
,
occupied

N

REs
,
total

,

where N REs,occupied denotes a number of occupied resource elements, N Res,total denotes a global number of available resource elements in the network cell, and resource elements are considered to be occupied based on a detected power being higher than a predefined threshold.

5. The method according to claim 1 , wherein said at least one wireless UE is configured to perform a further selection termed reselection.

6. The method according to claim 5 , wherein said at least one wireless UE is configured to perform said cell selection and reselection while in Idle mode.

7. The method according to claim 5 , further comprising performing said cell reselection by the following criterion:

R
s

=

10
⁢

log
⁡

[

f
⁡

(

Q

meas
,
s

)

×

(

1
-

L
s

/

Assignees

• Telefonica Sa

Inventors

• Lorca Hernando Javier

Classifications

• H04W72/52

  based on load · CPC title

• H04W24/02

  Arrangements for optimising operational condition · CPC title

• H04W36/22

  for handling the traffic · CPC title

• H04W48/20

  Selecting an access point · CPC title

• H04W16/08 Primary

  Load shedding arrangements · CPC title