Method for Congestion Avoidance in 4G Networks

• US 20120063315A1
• Filed: 09/15/2010
• Published: 03/15/2012
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: Wildfire.Exchange, Inc. (Plume Design, Inc.)
• Original Assignee: 4G Neuron, D.O.O.
• Inventors: LIKAR, Bojan, POSEL, Robert, KALAGASIDIS, Andreas, BESTER, Janez, KOS, Andrej, SEDLAR, Urban, MALI, Luka, STERLE, Janez, VOLK, Mojca
• Granted Patent: US 8,483,059 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 43/0882 Utilisation of link capacity
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04W 28/0205 at the air interface dynamic wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/0284 detecting congestion or overload during communication monitoring arrangements H04L43/00
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

This invention aims to avoid and resolve congestions in wireless 4G networks. The method is based on a central self-organizing network (SON) server, which dynamically changes neighbor lists on congested base station and on all base stations in vicinity. The procedure is triggered by measuring relative committed traffic rate and air interface utilization of the base station. When base station enters into congested state, it notifies the SON server. The SON server creates new neighbor lists for all base stations in the vicinity and removes the congested base station from these lists. With new neighbor lists propagated to mobile stations, the latter won'"'"'t scan and initiate handovers to the congested base station. The SON server additionally creates a new dense neighbor list and changes handover triggers settings of the congested base station. The mobile stations consequently find other handover opportunities and connect to different base stations. As the air interface resources are released, the base station leaves the congested state.

Claims

1. A method for congestion avoidance in 4G networks, consisting of

a) congestion detection, and

b) congestion avoidance procedure.

2. A method of claim 1, where congestion detection comprises the following steps:

a) measuring parameters of upload air interface utilization, download air interface utilization, relative committed upload rate and relative committed download rate,

b) using pairs of thresholds (hysteresis) to decide whether congestion has occurred.

3. A method of claim 1, where congestion avoidance procedure comprises the following steps:

a) entering the congested state,

b) exiting the congested state.

4. A method of claim 3, where entering the congested state comprises the following steps:

a) base station informing the SON server of the congestion by sending CONGESTION_INFORM message,

b) SON server receiving the CONGESTION_INFORM message,

c) SON server calculating dense neighbor list,

d) SON server sending the dense neighbor list to the congested base station,

e) SON server calculating new handover triggers configuration,

f) SON server sending the calculated handover triggers to the congested base station,

g) SON server removing the congested base station from the neighbor list of neighboring base stations,

h) SON server distributing the newly generated neighbor list to all neighboring base stations.

5. A method of claim 3, where exiting the congested state comprises the following steps:

a) base station informing the SON server the congestion has cleared by sending CONGESTION_RELEASE message,

b) SON server receiving the CONGESTION_RELEASE message,

c) SON server calculating sparse neighbor list,

d) SON server sending the sparse neighbor list to the congested base station,

e) SON server calculating new handover triggers configuration,

f) SON server sending the calculated handover triggers to the previously congested base station,

g) SON server placing the congested base station back to the neighbor list of neighboring base stations,

h) SON server distributing the newly generated neighbor list to all neighboring base stations.