ACCESS CONTROL FOR MACROCELL TO FEMTOCELL HANDOVER

• US 20100278141A1
• Filed: 05/01/2009
• Published: 11/04/2010
• Est. Priority Date: 05/01/2009
• Status: Active Grant

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Brisebois, Arthur Richard, Choi-Grogan, Yung Shirley, Huber, Kurt Donald
• Granted Patent: US 8,498,267 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04J 13/0062 Zadoff-Chu
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]

Abstract

System(s) and method(s) are provided to control access to a femtocell as part of handover of a mobile device from macrocell to femtocell. Macro network platform issues a handover (HO) request towards femto network platform and a single virtual femto node, which represents a plurality of femto access points (APs). Location estimate(s) for the mobile device drives selection of a target femto AP. Selection of the target AP results in acceptance of the HO request. The mobile device also can request macro-to-femto (MTF) handover. HO neighbor list(s) is generated by decoding a network-issued identifier for each femto APs in a set of femtocells, and selectively ranking each femto AP based at least on channel quality; access privileges of the mobile device to each of the identified femto APs determines selectivity. Validation of mobile device'"'"'s access right(s) drives acceptance of the MTF HO request to a top ranked femto AP.

Claims

14. A system that regulates access to a femto access point (AP) as part of handover of a mobile device from macrocell to femtocell, the system comprising:

at least a processor; and

a memory that retains code instructions that when executed by at least the processor confer at least part of the functionality of the following components;

a set of nodes that supplies a macro-to-femto (MTF) HO neighbor list that consists of a single virtual femto node entry that represents a set of one or more femto APs;

a handover manager that issues an MTF HO request towards a femto network platform and the virtual femto node;

a location component that provides a location estimate for the mobile device; and

a set of nodes that deliver a directive to the mobile device to handover to the virtual femto node when the MTF HO request is accepted.

1. A method for controlling access to an indoor-based access point (AP) during macro-to-indoor (MTI) handover (HO) of a mobile device, the method comprising:

employing at least a processor to execute code instructions retained in a memory, the code instructions when executed by at least the processor carry out the following acts;

receiving an MTI handover list with a single virtual indoor node entry, wherein the virtual indoor node is a logic structure that represents a plurality of indoor-based APs;

delivering an MTI HO request towards the received virtual indoor node;

supplying a location estimate for the mobile device associated with the MTI HO request; and

when acceptance of MTI HO request is received, commanding the mobile device to handover from macro coverage to the single virtual indoor node.

2. The method of claim 1, when acceptance of MTI HO request is received, further comprising routing traffic and signaling intended for the mobile device to macro-to-indoor handover connection.

3. The method of claim 1, wherein the location estimate is at least one of generated by the mobile device and based at least in part on a global navigation satellite system (GNSS) service.

4. The method of claim 1, wherein the location estimate is generated at least in part by one or more macro network components based at least in part on time-of-flight (TOF) measurements of propagation timing of wireless signals.

5. The method of claim 4, wherein the TOF measurements of propagation timing of wireless signals include at least one of round trip time (RTT) measurements, time of arrival (TOA) measurements, time difference of arrival (TDOA) measurements, angle of arrival (AOA) measurements.

6. The method of claim 1, further comprising:

receiving the MTI HO request linked to the mobile device served through a macro mobile network;

collecting the location estimate for the mobile device; and

based at least in part on the collected location estimate, selecting an indoor-based AP to serve the mobile device.

7. The method of claim 6, when the mobile device is within a predetermined range from the selected indoor-based AP, further comprising:

verifying a unique identifier for the mobile device is included in an access list linked to the selected indoor-based AP; and

when the unique identifier for the mobile device is included in the access list, accepting the received MTI HO request, and preparing for handover of the mobile device to the selected indoor-based AP.

8. The method of claim 7, wherein preparing for handover of the mobile device to the selected indoor-based AP includes at least one of reception and retention of data directed towards the mobile device;

reallocation or reservation of radio resources such as bandwidth;

adjustment of semi-persistent scheduling parameters;

configuration of at least one transceiver and associated communication circuitry to operate in a radio technology in which the mobile device operates;

or temporary augmentation of pilot signal(s) transmitted power so as to increase femto coverage area outside an intended confined space to increase likelihood of successful attachment by the mobile device.

9. The method of claim 6, when the mobile device is enabled with global positioning system (GPS) service, collecting the location estimate for the mobile device includes:

requesting GPS location data for the mobile device; and

receiving a GPS location estimate for the mobile device.

10. The method of claim 6, when the mobile device is not enabled with global positioning system (GPS) service, includes:

requesting location data for the mobile device based at least in part on one or more TOF measurements; and

receiving a location estimate for the mobile device based at least in part on the one or more TOF measurements.

11. The method of claim 1, further comprising:

receiving an MTI HO request toward a target indoor-based AP from the mobile device;

extracting an identity for the mobile device; and

when the mobile device is authorized to access the target indoor-based AP, authorizing the MTI HO thereto.

12. The method of claim 11, when the mobile device is authorized to access the target indoor-based AP, further comprising routing traffic and signaling intended to the mobile device to an MTI HO connection.

13. The method of claim 11, further comprising:

supplying a unique service are code (SAC) for each indoor-based AP in an indoor-based mobile network;

based at least in part on the SAC, configuring access privileges to each of the indoor-based APs in the indoor-based mobile network;

receiving the MTI HO to the target indoor-based AP;

accepting the received MTI HO request; and

preparing for MTI HO of the mobile device to the target indoor-based AP.

15. The system of claim 14, the system further comprising a set of nodes that conveys the MTF HO request.

16. The system of claim 14, when the MTF HO request is accepted, the mobile manager routes traffic and signaling intended for the mobile device to a configured MTF HO connection.

17. The system of claim 14, to provide the location estimate for the mobile device, the location component includes a global navigation satellite system (GNSS) component that requests the mobile device to deliver a GNSS-based location estimate when GNSS service is enabled in the mobile device.

18. The system of claim 14, to provide the location estimate for the mobile device, the location component includes a time-of-flight (TOF) component that effects TOF measurements of propagation timing of wireless signals between a macro serving base station and the mobile device.

19. The system of claim 18, wherein the location component includes one or more nodes that resolve a location estimate for the mobile device based at least in part on the effected TOF measurements.

20. The system of claim 18, wherein the TOF measurements of propagation timing of wireless signals include at least one of round trip time (RTT) measurements, time of arrival (TOA) measurements, time difference of arrival (TDOA) measurements, angle of arrival (AOA) measurements, the measurements performed at least in part.

21. The system of claim 20, when the mobile device is authorized to access the target indoor-based AP, the handover manager authorizes the MTI HO to the target indoor-based AP.

22. The system of claim 21, when the mobile device is authorized to access the target indoor-based AP, the handover manager routes traffic and signaling intended to the mobile device to an MTI HO connection.

23. The system of claim 20, further comprising:

an identification generator that supplies a unique service are code (SAC) for each indoor-based AP in an indoor-based mobile network; and

a server that configures access privileges for the mobile device to each of the indoor-based APs in the indoor-based mobile network based at least in part on the SAC.

24. The system of claim 23, wherein the handover component receives the MTI HO to the target indoor-based AP, and accepts the MTI HO request to the target indoor-based AP when the mobile device is authorized access thereto.

25. The system of claim 24, upon acceptance of the MTI HO request, the handover component performs at least one of the following:

configures a user data routing path between a control node that can transport data and signaling to the target indoor-based AP and the target indoor-based AP;

or

commands the target indoor-based AP to prepare for the MTI HO, wherein preparation can include at least one of reception and retention of data directed towards the mobile device;

reallocation or reservation of radio resources such as bandwidth;

adjustment of semi-persistent scheduling parameters;

configuration of at least one transceiver and associated communication circuitry to operate in a radio technology in which the mobile device operates;

or temporary augmentation of pilot signal(s) transmitted power in the target indoor-based AP so as to increase coverage area outside of an intended confined space to increase likelihood of successful attachment by the mobile device.

18-1. The system of claim 15, further comprising:

a set of nodes that receives the MTF HO request;

a handover component that requests a location estimate for the mobile device, wherein the request is based at least in part on whether a global positioning service (GPS) is enabled in the mobile device; and

a selector component that identifies an indoor-based AP to serve the mobile device based at least in part on the collected location estimate.

19-2. The system of claim 18, when the mobile device is within a predetermined range from the selected indoor-based AP, the handover component performs at least one of the following:

accepts the received MTI HO request;

or

prepares for handover of the mobile device to the selected indoor-based AP.

20-3. The system of claim 14, wherein the handover manager receives an MTI HO request to a target indoor-based AP from the mobile device, and extracts an identifier for the mobile device, wherein the identifier is at least one of an international mobile subscriber identity (IMSI), a temporary mobile subscriber identity (TMSI), packet TMSI (P-TMSI), an international mobile equipment identifier (IMEI), a mobile directory number (MDN), a mobile identification number (MIN), a Telecommunications Industry Association (TIA) electronic serial number (ESN), or a multi-bit identification number like the mobile identity number (MEID).

26. A method for handing over a wireless device from macrocell to femtocell, the method comprising:

employing one or more processors to execute code instructions retained in a memory, the code instructions when executed by at least the processor carry out the following acts;

measuring pilot signal from a set of femto access points (APs);

reporting a single virtual femto node in a handover neighbor list, wherein the virtual femto node represents one or more femto APs;

receiving an indication to supply location data;

when location service data is enabled, conveying a location estimate; and

receiving a command to handover to a specific femto AP within the virtual femto node, wherein the specific femto AP is selected based at least in part on the location estimate.

27. The method of claim 26, when location service is disabled, further comprising:

receiving an indication to deliver time-of-flight signaling related to measurements of timing propagation of wireless signal(s) between the wireless device and a serving macrocell; and

delivering the TOF signaling.

28. The method of claim 26, wherein the specific femto AP is located within a preconfigured range from the ground truth of the wireless device as revealed by the location estimate.

29. The method of claim 26, further comprising:

attaching to the specified femto AP; and

detaching from a serving macrocell.

30. The method of claim 26, further comprising:

scanning pilot signals from a first set of femto APs;

identifying a service area code (SAC) for each femto AP in the first set of femto APs;

generating a target femtocell list in accordance at least in part with measured pilot signal from a second set of femto APs selected in accordance at least in part with an identified set of SACs; and

conveying a request to handover to a specific femto AP within the target femtocell list.

31. The method of claim 30, when the request is granted, further comprising:

attaching to the specified femto AP; and

detaching from a serving macrocell.

32. A mobile device, comprising:

a handover component that reports a single virtual femto node in a handover neighbor list, wherein the virtual femto node represents a plurality of femto APs; and

a technology selector that switches mode of operation of the mobile device to generate a GNSS-based location estimate thereof when GNSS service is enabled.

33. The mobile device of claim 32, further comprising a memory that retains an access list that determines at least in part access privileges to a femto AP, wherein the access list includes a network-issued identifier for the femto AP.

34. The mobile device of claim 33, wherein the handover component includes a scanner component that decodes the network-issued identifier for the femto AP.

35. The mobile device of claim 34, when the network-issued identifier for the femto AP indicates that the mobile device is allowed to access the femto AP, the scanner component measures a set of pilot signals.

36. The mobile device of claim 35, when the network-issued identifier for the femto AP indicates that the mobile device is allowed to access the femto AP, further comprising:

a component that determines channel quality for the femto AP based at least in part on the measured set of pilot signals; and

a target generator that ranks the femto AP in accordance at least in part with the determined channel quality thereof as part of generation of a handover neighbor list.

37. The mobile device of claim 36, wherein the handover component includes a handover driver that conveys a request to handover to a ranked femto cell within a handover neighbor list.

38. The mobile device of claim 37, when the request to handover is accepted, the handover driver attaches to a target femto AP and detaches from a service macro base station, wherein the target femto AP can be specified as part of acceptance signaling.