1. A method for setting up a communication with a given mobile station served by a radio access network, wherein the radio access network defines a plurality of wireless coverage areas, the method comprising:
receiving an indication of a location of the given mobile station;
using the location of the given mobile station to identify at least first and second wireless coverage areas associated with the given mobile station;
receiving a request to set up a communication with the given mobile station;
in response to receiving the request, reserving a channel for the communication with the given mobile station in each of the identified first and second wireless coverage areas;
in each of the identified first and second wireless coverage areas, transmitting a channel assignment message specifying the channel reserved for the communication in the wireless coverage area without first paging the given mobile station;
receiving an indication that the given mobile station has accepted assignment of the channel reserved for the communication in the identified first wireless coverage area; and
in response to receiving the indication, releasing the channel reserved for the communication in the identified second wireless coverage area.
2. The method of claim 1, wherein the channel assignment message contains an identifier of a mobile station, and wherein the given mobile station accepts the channel assignment message if the identifier in the channel assignment message matches an identifier of the given mobile station.
3. The method of claim 2, wherein the identifier in the channel assignment message is selected from the group consisting of:
a mobile identification number;
an international mobile subscriber identity; and
a unicast access terminal identifier.
4. The method of claim 1, wherein the channel assignment message is selected from a group consisting of:
a 1 xRTT channel assignment message; and
an EV-DO traffic channel assignment message.
5. The method of claim 1, wherein the channel assignment message contains one or more of a carrier frequency, a PN offset, a Walsh code, and a MAC identifier.
6. The method of claim 1, wherein receiving the indication of the location of the given mobile station comprises receiving a GPS location reading from the given mobile station.
7. The method of claim 1, wherein receiving the indication of the location of the given mobile station is selected from a group consisting of
receiving the indication of the location periodically according to a schedule; and
receiving the indication of the location in response to a change in location by the given mobile station.
8. The method of claim 1, further comprising:
storing the location of the given mobile station.
9. The method of claim 1, wherein using the location of the given mobile station to identify at least first and second wireless coverage areas associated with the given mobile station comprises:
maintaining information about the first and second wireless coverage areas of the radio access network; and
comparing the location of the given mobile station to the information about the first and second coverage areas.
10. The method of claim 1, wherein at least one of the identified first and second wireless coverage areas encompasses the location of the given mobile station.
11. The method of claim 1, wherein each of the identified first and second wireless coverage areas comprises a cell sector.
12. The method of claim 1, wherein using the location of the given mobile station to identify the at least first and second wireless coverage areas associated with the given mobile station comprises using the location of the given mobile station to identify the at least first and second wireless coverage areas associated with the given mobile station in response to receiving the request to set up a communication with the given mobile station.
13. A radio access network comprising:
one or more antenna structures for communicating with mobile stations located in a plurality of wireless coverage areas;
a communication interface for communicating with one or more networks;
a processor;
data storage; and
program instructions stored in the data storage and executable by the processor to carry out functions including:
receiving an indication of a location of a given mobile station;
using the location of the given mobile station to identify at least first and second wireless coverage areas associated with the given mobile station;
receiving a request to set up a communication with the given mobile station via the communication interface;
in response to receiving the request, reserving a channel for the communication with the given mobile station in each of the identified first and second wireless coverage areas;
in each of the identified first and second wireless coverage areas, transmitting a channel assignment message specifying the channel reserved for the communication in the wireless coverage area without first paging the given mobile station;
receiving an indication that the given mobile station has accepted assignment of the channel reserved for the communication in the identified first wireless coverage area; and
in response to receiving the indication, releasing the channel reserved for the communication in the identified second wireless coverage area.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A shield for use in a disc drive storage system comprising:
a ferromagnetic (FM) layer having a patterned shape and a domain configuration, defined by a plurality of local magnetic domains that are stabilized in accordance with the patterned shape; and
an antiferromagnetic (AFM) layer adjacent the FM layer and annealed to imprint thereon the stabilized local magnetic domains of the FM layer, whereby stability of the domain configuration of the FM layer is increased.
2. A read head for use in a disc drive storage system comprising:
a top and bottom shield, wherein at least one of the top shield and bottom shields is formed in accordance with the shield of claim 1; and
a read element formed between the top and bottom shields adjacent an air bearing surface.
3. A disc drive storage system including the read head of claim 2.
4. The shield of claim 1, wherein the FM layer is formed of at least one material selected from a group consisting of NiFe, FeSiAl, FeN, CoFe, CoNiFe, and CoZrNb.
5. The shield of claim 1, wherein the AFM layer is formed of at least one material selected from a group consisting of NiMn, FeMn, PtMn, IrMn, PtPdMn, and NiO.
6. The shield of claim 1, wherein:
the FM and the AFM layers form a first shield layer; and
the shield includes at least a second shield layer formed of adjoining second FM and AFM layers and a spacer layer between the first and second shield layers.
7. The shield of claim 6, wherein the spacer layer is formed of a non-magnetic material.
8. The shield of claim 6, wherein:
the second FM layer includes a patterned shape and a domain configuration, defined by a plurality of local magnetic domains that are stabilized in accordance with the patterned shape; and
the second AFM layer is annealed to imprint thereon the stabilized local magnetic domains of the second FM layer, whereby stability of the domain configuration of the second FM layer is increased.
9. A method of forming a magnetic shield for a read element of a read head, comprising steps of:
(a) forming adjoining ferromagnetic (FM) and antiferromagnetic (AFM) layers, the FM layer having a domain configuration that is defined by a plurality of local magnetic domains;
(b) patterning at least the FM layer into a patterned shape;
(c) stabilizing the domain configuration of the FM layer in accordance with the patterned shape; and
(d) heating the AFM layer beyond a blocking temperature to imprint thereon the stabilized local magnetic domains of the FM layer, whereby stability of the stabilized domain configuration of the FM layer is increased.
10. The method of claim 9, wherein the patterning step (b) includes a at least one processing technique selected from a group consisting of etching, milling, and lapping.
11. The method of claim 9, wherein the stabilizing step (c) includes demagnetizing the FM layer.
12. The method of claim 11, wherein:
the FM layer has an easy axis and a hard axis; and
the demagnetizing step involves applying a decaying sinusoidal magnetic field that is substantially oriented along one of the easy axis and the hard axis of the FM layer.
13. The method of claim 9, wherein the annealing step (d) takes place in a substantially zero magnetic field environment.
14. The method of claim 9, wherein a magnetic field is applied during the annealing step (d) to increase unidirectional anisotropy of the domain configuration of the FM layer.
15. A method of forming a read head comprising steps of:
forming at least one of a top and a bottom shield in accordance with the method of claim 9; and
forming a read element between the top and bottom shields.
16. A read head, comprising:
a read element formed between patterned top and bottom shields, at least one of which includes a ferromagnetic (FM) layer having a stabilized domain configuration; and
wherein at least one of the top and bottom shields includes a stabilizing means for preventing significant shifts to the stabilized domain configuration after exposure to a strong magnetic field.
17. The read head of claim 16, wherein:
the stabilized domain configuration of the FM layer is defined by a plurality of local magnetic domains; and
the stabilizing means includes an antiferromagnetic (AFM) layer adjacent the ferromagnetic layer and annealed to have local unidirectional anisotropies in accordance with the local magnetic domains of the stabilized ferromagnetic layer.
18. The read head of claim 16, wherein the FM layer is formed of at least one material selected from a group consisting of NiFe, FeSiAl, FeN, CoFe, CoNiFe, and CoZrNb.
19. The read head of claim 17, wherein the AFM layer is formed of at least one material selected from a group consisting of NiMn, FeMn, PtMn, IrMn, PtPdMn, and NiO.