Transcript 802.16_core_network

Network Discovery and
Selection/Re-selection
OUTLINE
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Network Model
Use-case Scenario
Solution
IP Addressing
Network Model
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ASN: Access Service Network
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NAP: Network Access Provider
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A ASN contains BSs and ASN-GWs.
A NAP contains one or more ASNs.
NSP: Network Service Provider
Network Model
Visited NSP
R2
Home NSP
R2
R3
R1
SS/
MSS
R5
ASN
CSN
CSN
SS
R4,
Another ASN
NAP
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ASP Network OR
Internet
ASP Network OR
Internet
Deployment case
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NAP Sharing
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More than one NSPs shares the same NAP
NAP+NSP
Use-case Scenario
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1.First-time use
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2.Initial network entry
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3.Network Re-entry
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4.MSS transitions across NAP coverage areas
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The same as handoff within the same WiMAX NAP
Due to user movement or confounding factor, MSS elects to transition another NAP
Solution
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In a WiMAX network, a full network discovery and selection procedure
includes four steps:
1.WiMAX NAP Discovery
2.NSP Access Discovery
3.NSP Enummeration and Selection
4.ASN Attachment based on NSP selection
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Two WiMAX network selection modes are defined, automatic and
manual.
Solution (1)
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WiMAX NAP Discovery
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An SS/MS detects available NAPs by scanning and decoding DL-MAP of
ASN on detected channel.
The most significant 24-bit value of “operator ID” within the “BS ID”
parameter in the DL-MAP message is the NAP Identifier.
In NAP+NSP deployment case, NAP identifier shall be identical with NSP
identifier.
NAP discovery is based on the procedures defined in IEEE Std 802.16-2004 [x1]
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Solution (2)
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NSP Access Discovery
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The SS/MS shall sequentially perform association with each NAP for the
purpose of discovering the supported NSPs
The ASN transmits the NSP ID list message no less than once every five
seconds.
For SS/MS with configuration information that includes a list of NAP + NSP
unitary mappings, WiMAX NAP Discovery of the NAP Identifier is sufficient
to provide NAP and NSP.
Solution (3)
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NSP Enumeration and Selection
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Manaul or Automatic mode
If displayed, NSPs from the list of available NSPs shall be presented in the
following order:
a) Home NSP
b) NSPs in the "User Controlled NSP Identifier list" data file in the SS/MS
c) NSPs in the "Operator Controlled NSP Identifier list" data file
d) Any other NSP in random order
The signal quality shall not be used as a parameter for NSP Selection
Solution (4)
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ASN Attachment based on NSP selection
An SS/MS indicates its NSP selection by attaching to an ASN associated
with the selected NSP, and by providing its identity and home NSP domain
in form of NAI.
– The ASN uses the NAI to determine the next AAA hop to where the MS’s
AAA packets should be routed.
NAI (Network Access Identifier) Example:
– MS_1 uses a normal/root NAI (i.e., user-name@NSP_1.com)
– MS_2 needs to construct a decorated NAI (e.g., NSP_4!user-name
@NSP_1.com)
ASN Sharing
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[RFC4282]
ASN of
NAP_1
MSS_1 of
NSP_1
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MSS_2 of
NSP_4
CSN of
NSP_1
CSN of
NSP_2
CSN of
NSP_3
CSN of
NSP_4
Solution (5)
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NSP Access Discovery(2) and NSP Enumeration(3) and Selection
may well occur concurrent to WiMAX NAP Discovery(1) .
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There is no requirement that an SS/MS discover all NAPs and NSPs.
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An SS/MS may stop the discovery process on discovery of a NAP and
NSP meeting the SS/MS NSP Enumeration and Selection criteria and
proceed to ASN Attachment.
Configuration Information in SS/MSS
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User/Operator controlled NAP Identifier list
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User/Operator controlled NSP Identifier list
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The lists are used to select a NSP.
NAP/NSP mapping list
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Information useful in NAP Discovery including channel, center frequency,
and PHY profile
Network deployment mode
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Indicating whether the list of supported NSPs for a NAP is changed
Physical information:
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Indicating the supported NSPs per NAP
NSP Count
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Determining priority order of performing NSP Access Discovery
procedure among if there are more than one available NAP.
Indicating the Network deployment mode of each NAP, i.e. NAP+NSP
mode or NAP sharing mode.
IP Addressing
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The functional entity residing in ASN-GW is a DHCP relay.
Functional Decomposition for PoA from Visited NSP
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Functional Decomposition for PoA from Home NSP
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IP configuration setup
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The functional entity residing in ASN-GW is a DHCP relay.
Access authentication:
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the network assigning the PoA address is determined.
MSS
BS
Access Authentication
DHCP
Proxy Relay
DHCP
Server
H-AAA
Access Authentication (DHCP Server @)
1) Access Authentication
2) DHCP Discove r
3) DHCP Discove r
(giaddr)
4) DHCP Offer
(MSS IP@)
5) DHCP offer (MSS IP@ )
6) DHCP Reques t
7) DHCP Reques t
8) DHCP Ack
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DHCP
Gating
9) DHCP Ack
Through DHCP
or AAA at
Authorization
time