System and method of controlling network traffic using preamble detection and automated optimization of random access channel parameters

Patent metadata

Field	Value
Publication number	US-9913295-B2
Application number	US-201615191756-A
Country	US
Kind code	B2
Filing date	Jun 24, 2016
Priority date	Jun 24, 2016
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

Detecting physical random access channel (RACH) preambles is accomplished by computing a correlation power profile based on received RACH preambles, where the correlation power profile values may be sorted. A weight factor is computed for each of the correlation power profile values based on a normalized RACH detection threshold. Outlier peaks of the correlation power profile values are selected based on the weight factor. The outlier peaks to the first set of RACH signatures are mapped in order to identify a user equipment (UE) that is associated with one of the received RACH preambles. Network traffic is then controlled for network communications associated with the identified UE.

First claim

What is claimed is:

1. A method of preamble detection to control network traffic in a communication network, comprising:
detecting, by at least a first processor of at least a first network node, physical random access channel (RACH) preambles, by performing the steps of,
computing a correlation power profile based on a set of received RACH preambles,
sorting correlation power profile values,
computing a weight factor for each of the correlation power profile values based on a normalized RACH detection threshold,
selecting outlier peaks of the correlation power profile values based on the weight factor,
mapping the outlier peaks to the first set of RACH signatures in order to identify at least one UE that is associated with one of the received RACH preambles; and

controlling, by the first processor, the network traffic of network communications associated with the at least one identified UE.

2. The method of claim 1 , wherein the detecting of the RACH preambles is accomplished using a forward consecutive mean excision (FCME) method.

3. The method of claim 1 , wherein,
the detecting of the RACH preambles further includes,
collecting noise rise information and preamble miss information for a set of transmitted RACH preambles,
computing an overall average noise rise for the communication network based on the collected noise rise information,
computing an average missed detection ratio for the communication network using the collected preamble miss information,
determining a target receiver power and a power ramp-up using the average nose rise and the average missed detection ratio.

4. The method of claim 1 , wherein,
the detecting of the RACH preambles further includes determining the normalized RACH detection threshold by performing the steps of,
collecting preamble false alarm ratio information,
computing an average false alarm rate for the communication network based on the preamble false alarm ratio information, and
determining the normalized RACH detection threshold based on the average false alarm rate,

the controlling the network traffic further includes,
broadcasting the normalized RACH detection threshold to UEs of the communication network.

5. The method of claim 1 , further comprising:
collecting a contention ratio information,
computing an average contention ratio for the communication network based on the collected contention ratio information,
determining the opportunity period based on the average contention ratio,
wherein the controlling the network traffic further includes,
broadcasting the opportunity period to UEs of the communication network.

6. The method of claim 3 , wherein,
repeating the steps of collecting noise rise information and preamble miss information, and repeating the steps of computing an overall average noise rise and an average missed detection ratio until the determined target receiver power and the power ramp-up remain constant; and
wherein the controlling the network traffic further includes,
broadcasting the target receiver power and a power ramp-up to UEs of the communication network;

wherein the detecting of the RACH preambles further includes determining the normalized RACH detection threshold, once the determined target receiver power and the power ramp-up remain constant, by performing the steps of,
collecting preamble false alarm ratio information,
computing an average false alarm rate for the communication network based on the preamble false alarm ratio information, and
determining the normalized RACH detection threshold based on the average false alarm rate,

wherein the controlling the network traffic further includes,
broadcasting the normalized RACH detection threshold to UEs of the communication network.

7. The method of claim 6 , further comprising:
repeating the steps of collecting preamble false alarm ratio information and computing an average false alarm rate until the determined normalized RACH detection threshold remains constant; and
wherein the detecting of the RACH preambles further includes determining an opportunity period, once the determined target receiver power, the power ramp-up, and the normalized RACH detection threshold remain constant, by performing the steps of,
collecting a contention ratio information,
computing an average contention ratio for the communication network based on the collected contention ratio information,
determining the opportunity period based on the average contention ratio,
wherein the controlling the network traffic further includes,
broadcasting the opportunity period to UEs of the communication network.

8. The method of claim 1 , wherein,
the at least a first processor of at least a first network node includes a plurality of processors, each of the plurality of the processors being associated with a network node dedicated to a respective sector within the communication network,
the detecting of the RACH preambles further includes,
each of the processors collecting noise rise information and preamble miss information for a set of transmitted RACH preambles for the respective sector,
each of the processors computing an overall average noise rise based on the collected noise rise information for the respective sector,
each of the processors computing an average missed detection ratio, for the respective sectors, using the collected preamble miss information from each respective sector,
each of the processors sharing the overall average noise rise and the average missed detection ratio with at least one of the other processors, of the plurality of processors, which is a neighbor processor,
each of the processors determining a target receiver power and a power ramp-up, for the respective sectors, using the shared average nose rise and the shared average missed detection ratio.

9. The method of claim 8 , further comprising:
repeating the steps of each of the processors of the respective sectors collecting noise rise information and preamble miss information, and repeating the step of computing an overall average noise rise and an average missed detection ratio until the determined target receiver power and the power ramp-up remain constant;
wherein the controlling the network traffic further includes,
each of the processors broadcasting the target receiver power and a power ramp-up to UEs for the respective sectors;

wherein the detecting of the RACH preambles further includes determining the normalized RACH detection threshold, once the determined target receiver power and the power ramp-up remain constant, by performing the steps of,
each of the processors collecting preamble false alarm ratio information for the respective sectors,
each of the processor computing an average false alarm rate, for the respective sectors, based on the preamble false alarm ratio information, and
each of the processors determining the normalized RACH detection threshold, for the respective sectors, based on the average false alarm rate,

wherein the controlling of the network traffic further includes each of the processors broadcasting the normalized RACH detection threshold to UEs for the respective sectors.

10. The method of claim 9 , further comprising:
repeating the steps of each of the processors of the respective sectors collecting preamble false alarm ratio information and computing an average false alarm rate, until the determined normalized RACH detection threshold remains constant;
wherein the detecting of the RACH preambles further includes determining the opportunity period, once the determined normalized RACH detection threshold remains constant, by performing the steps of,
each of the processors collecting a contention ratio information fo

Assignees

• Tavares Marcos
• Uptegrove Dirck
• Samardzija Dragan
• Alcatel Lucent Usa Inc

Inventors

• Tavares Marcos
• Uptegrove Dirck
• Samardzija Dragan

Classifications

• H04W74/0833 Primary

  Random access procedures, e.g. with 4-step access · CPC title

• H04W28/02

  Traffic management, e.g. flow control or congestion control · CPC title

• H04W74/002

  Transmission of channel access control information · CPC title

• H04L7/042

  Detectors therefor, e.g. correlators, state machines (digital correlators in general G06F17/15) · CPC title

• H04L27/2663

  Coarse synchronisation, e.g. by correlation · CPC title