Transcript 802.21 - TGu Joint Session

IEEE 802.21 MEDIA INDEPENDENT HANDOVER
DCN: 21-06-0817-01-0000
Title: 802.21 – TGu Joint Discussions
Date Submitted: December, 2006
Presented at IEEE 802.21 session #17 in Dallas, Texas.
Authors or Source(s):
Vivek Gupta
Abstract: Inputs from 802.21 to questions from TGu
1
TGu Inputs
• 11-06-1492-00-000u tgu-802-21-joint-session-update-tgunetwork-selection-mih-support
• 11-06-1543-00-000u-planning-november-2006-joint-sessionbetween-802-21-and-802-11u
2
Discussion Items
1. Initial Network Selection vs Handovers
2. Information Elements Organization
3. Static vs Dynamic IEs
4. Queries
5. Maximum message length in State 1 Issues
6. MIH Events
7. MLME primitives
8. Security Implications
9. Next Steps
3
1. Initial Network Selection vs Handovers
• 802.21 IS Applicable in two cases:
 When
MN is ALREADY connected to some other network and needs
to Handover an existing connection to 802.11
o
o
o
The 802.11 radio may be in OFF state in this case
When evaluating 802.11 networks the Network Selection entity (in MN or
Network) may need to know more about 802.11 network properties even
before deciding to Power On the 802.11 radio
802.21 IS can provide these properties
 When
MN is NOT connected to any network and needs to select an
appropriate 802.11 network to connect to
o
802.11 may be the DEFAULT radio to connect to on Power up or 802.11
may be the only network coverage available in that area
4
1. Initial Network Selection vs Handovers
• During the joint session of Sept, 802.21 we discussed the difference between
initial network selection and handover. Please provide details on what is
different that impacts our interface (802.11 > 802.21)
• Does 802.21 expect 802.11u to provide any service beyond network
selection which is already defined?
• E.g., does 802.21 expect 802.11u to pre-provision QoS?
• From 802.21 perspective there is NO difference in the two cases
• IS can be used in both state-1 and state-3
5
2.Information Elements Organization
• Multiple Networks of different Network_Type may be
available in a particular geographical area:
•
802.11, 802.16, Cellular
• For each Network_Type (such as 802.11) there may be
several operators, providing several instances of a
particular Network_Type
•
•
Operator_A, Operator_B, etc. may all have 802.11 network
The properties of these network instances may be different
•
•
802.11 Network Standards they support (.11a/b/e/g/i/n/p/r/s/u/v…)
Cost, Security, Roaming Agreements etc. for these networks may be different
• For each of the above Network Instance, there are
different PoAs (APs for 802.11)
•
•
The properties of these APs may differ
Location, Subnet Information, Capabilities, etc.
• Feedback from Dallas: Most of PoA information may be
common. Provide single instance of this information at
Access Network level
6
2.Information Elements Organization
List of Access Network Types
(802.11, 802.16, Cellular)
Access Network Properties
802.11 Network from Operator_A
802.11 Network from Operator_B
802.16 Network from Operator_A
802.16 Network from operator_C
PoA Specific Properties
Properties of each AP/BS
7
Information Elements-1
Information
Element
Description
Comments
General Network Information (List of Networks)
Network Type
Operator
Identifier
Service
Provider
List of all Network types
that are available in a
particular area
Core Network Identifier
E.g., 802.11, 802.16, CDMA,
UMTS Networks (Table-8)
Provider of services
Service (such as VoIP)
Provider name
Operator Type + Operator
name
(May not be applicable in all
cases)
8
Information Elements-2
Information
Element
Description
Comments
Access Network specific Information
Access Network
Identifier
Used to uniquely identify
access network.
For example ESSID in case of 802.11
Roaming Partners
Roaming partners that have
agreement with Access
Network operator
Access Network specific
applicable revisions to base
standards
Cost of accessing the network
SSPN partners for 802.11
Network
Standards
Cost
Security
QoS
(a/b/e/g/i/k/n/p/r/s/t/u/v/….)
Currency+Unit+Value+Service-Info
(Table-10)
Authentication Methods and
Cipher Suites
Packet Transfer Delay
(Min/Max/Avg)
Jitter
Packet Loss Rate
Packet Error Rate
9
Information Elements-3
Information
Element
Description
Comments
Address
PoA specific Information
MAC Address
BSSID
Location
PoA location
Data Rate
Min-Max Range
Channel
Range
Subnet
Information
PoA
Capabilities
IP Config
Methods
Spectrum Range
See Table 11,12,13
List of subnets to which
PoA belongs
Services Supported
DHCP, etc.
10
2.Information Elements Organization
• Changes in Draft:
• Change organization of IEs and provide common PoA
information as part of Access Network Properties
• Location of Network
• Data Rate
• PoA Capabilities (Services supported by network)
• IP Config Methods
• Leave following as PoA properties
• MAC Address
• Channel Range
• Location of PoA
• Subnet Information
11
3. Static vs Dynamic IEs
• What 802.11 IEs should be stored on Information Server?
• Guiding principles
• Put the minimum information needed by STA for network selection
and network identification—minimizes synchronization problems
between configuration of 802.11 AN and 802.21-IS database
• Include support for two types of queries:
•
•
Remote query (state 3 query): I’m in San Francisco and want to find out what
hotspots are in Melbourne
Local query (state 1 query): I can see 3 hotspots now, which one is the best to
associate with?
 802.21
•
IS does NOT distinguish between Access Network States
Do not include 802.11 AN dynamic information; examples include:
•
•
•
Channel number,
Transmit power
Traffic Load
 None
of the above are included in IS
12
3. Static vs Dynamic IEs
• What 802.11 IEs should be stored on Information Server?
• Fundamental binding provided by 802.21-IS
• SSPN to WLAN
• WLAN identified by {SSID, ESSID} (Supported)
• Recommended information to store in 802.21 database:
• SSPN name/realm (Supported)
• SSPN roaming partners (Supported)
• Interworking services by SSPN (including emergency services)
(Supported)
•
802.11 AN parameters:



•

Location
Country/regulatory domain
{SSID, ESSID}
PHY types supported
802.11e QoS support
(Supported Phy types can be obtained from Network_Standards)
13
3. Static vs Dynamic IEs
• QoS Parameters in current 802.21 draft:
•
•
•
•
•
•
•
•
Throughput
Link Packet Error Rate
Supported number of Classes of Service
Min Packet Transfer Delay
Avg Packet Transfer Delay
Max Packet Transfer Delay
Packet Transfer Delay Jitter
Packet Loss Rate
• Does it make sense to add these?
14
4. Queries
• TLV Containers
• List of Access Networks Container
•
•
Access Network Container
•
•
TYPE_CONTAINER_LIST_OF_NETWORKS
TYPE_CONTAINER_NETWORK
PoA Container
•
TYPE_CONTAINER_POA
• Other Query parameters
• Client Location
• Radius of interest for networks
• Queries
• Any IE can be queried.
• Any number of IEs can be queried in same request
15
4. Queries
• Query Examples
• What WLANs support my subscriptions?
• STA: provides list of subscriptions
• 802.21-IS: provides list of {SSPN, SSID, ESSID} where SSPN’s
includes roaming partners
•
Need to add
• Is emergency service supported on this WLAN?
• STA: provides ESSID(s)
• 802.21-IS: provides list of {SSPN, SSID, ESSID}
•
Need to add
• What interworking services are supported on this WLAN?
• STA: provides ESSID(s)
• 802.21-IS: provides list of {SSPN, SSID, ESSID, interworking services}
•
Supported (PoA capabilities IE)
16
4. Queries
• Query Examples
• Is VoIP services provided on this WLAN?
• STA: provides ESSID(s)
• 802.21-IS: provides list of {SSPN, SSID, ESSID} which
support VoIP
• Note that VoIP is just an example; query could be for any
interworking service
•
Need to add
• I’m traveling to Melbourne, what hotspots are located there?
• STA: provides location (latitude, longitude), search radius
• 802.21-IS: provides list of {SSPN, SSID, ESSID}
• This could potentially generate a lengthy query response
•
Supported
17
5. Maximum Message Length Issues
• From TGu:
• Proposal to define a maximum message length for state-1
query—merge proposal with 802.11u proposal during meeting
• 802.11u should present the requirements we’ve identified for
using GAS will be met by 802.21 services
• Message lengths
• Freshness of information
• Synchronization between AP configuration data and 802.21IS database
• Contribution IEEE 802.11-06/1784r0 by Dave Stephenson et al
18
6. Event Service
• Link Layer Events
• MIH Events
•
•
•
Can be local or remote
Remote MIHF entity has to subscribe for events it is interested in
Delivery through MIHF protocol
19
6. Event Service/MLME Primitives
No
Event Name
1
2
3
Link Up
Link Down
Link Going
Down
Link Detected
Link Parameters
Change
L2 Connection established
L2 Connection is broken
L2 connection breakdown imminent
Link Event
Rollback
Link SDU
Transmit Status
Event rollback
8
Link Handover
Imminent
L2 intra-technology handover imminent
(subnet change). Notify Handover information
without change in link state.
9
Link Handover
Complete
Notify Handover state
4
5
6
7
Description
New L2 link has been found
Change in specific link parameters has
crossed pre-specified thresholds (Link Speed,
Quality metrics)
Improve handover performance through local
feedback as opposed to waiting for end-toend notifications
New MLME
Primitive
Exists
N/A
May be
Needed
N/A
May be
Needed
May be
Needed
N/A
May be
Needed (TGr
may be
covering this)
May be
Needed
20
8.Security Implications
• Describe security implications of session hand-off between networks (e.g.,
Wi-Fi to Cellular)
• For example, if Wi-Fi network only has WEP-40 encryption, will cellular
network accept the handoff?
• The STA needs to know acceptable security levels for different
technologies and provide appropriate credentials.
21
Next Steps
• Prepare text contribution highlighting these issues
• File appropriate comments as part of 802.21 LB #1b
22
Backup
23
802.11 based Reference Network
NAP NOC
SSPN #1 NOC
802.21 IS AAA
802.21 IS AAA
MIH
SSPN #1
Core Network
MIH
NAP
Core Network
SSPN #2 NOC
Internet
802.21 IS AAA
SSPN #2
Core Network
Hot Spot #1
Hot Spot #N
Use 802.21 as Protocol for Network Selection
24
MIHF Protocol
MIHF Fixed
Header
MIHF Variable
Header
MIHF Payload
MIH Function Frame
Opcode
(2)
SID
(4)
Octet 1
VER Ack
MIHF
Fixed F
Header
MIHF
Variable
Load
(4)
Octet 2
Ack
Req (1) Rsp(1)
Reserved
(10)
Transaction ID
(16)
Octet 3
Action ID
(10)
Octet 4
MIH Message ID
(16)
Va riable Load Length
(16)
MIHF VaVariable Header
(contains Header Identifiers in TLV format)
MIHF Payload
(contains other service specific TLV s)
25
MIHF Protocol – Fixed Header
Field Name
Size
(bits)
Description
Version
4
0: Not used, 1: Current Version, 2-15 Reserved
ACK_Req
1
Request an Acknowledement (N/A for 802.11)
ACK_Rsp
1
Respond to Acknowledgement (N/A for 802.11)
Reserved
10
MIH Message ID
16
Combination of following three bit-fields
- Service Id (SID)
4
1: System Mgmt
2: Event Service
3: Command Service 4: Information Service
- Operation Code (Opcode)
2
1: Request, 2:Response, 3:Indication
- Action Identifier (AID)
10
Specific Action to be taken
Transaction ID
16
To match Requests and Response
Variable Load Length
16
Total length of Variable load field
26
MIHF IS Query Request
MIH_Get_Information.Request
-- IS Info Query Type
-- IS Query Parameters
Information
Service
Request
MIH_Get_Information
Fixed Header
Ver (0)
Ack (0)
Rsp (0)
Reserved (0)
Transaction Identifier
Payload
SID (4)
OpCode (1)
AID (21)
Payload Length
IS Info Query Type
Type = 4
Length = 1
Value = 1 (TLV)
Type= 36
Length = ?
Value = 1 (TLV Parameters)
IS Query Parameters: Location, Span/Radius, etc.
27
MIHF IS Query Response
MIH_Get_Information.Response
-- IS Info Query Type
-- IS Response Parameters
Information
Service
Response
MIH_Get_Information
Fixed Header
Ver (0)
Ack (0)
Rsp (0)
Reserved (0)
Transaction Identifier
Payload
SID (4)
OpCode (2)
AID (21)
Payload Length
IS Info Query Type
Type = 4
Length = 1
Value = 1 (TLV)
Type= 37
Length = ?
Value = 1 (TLV Parameters)
IS Response Parameters…..
28