March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 1

doc.: IEEE 802.11-04/0351r0

Submission

Fast Roaming Study Group: Proposal for Task Group Name

Haixiang He, Nortel Networks

Darwin Engwer, Nortel Networks

Simon Barber, Instant802 Networks

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 2

doc.: IEEE 802.11-04/0351r0

Submission

Where are we here?

• Provide a solution to address the PAR comments filed by 802.21 relating to the name of the 802.11r (new mobility) task group.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 3

doc.: IEEE 802.11-04/0351r0

Submission

Goal

• We should use a name that makes sense and does not cause confusion.

• We can redefine a well known name. But is it a good idea?

• If we can find an appropriate name, then we don’t need to redefine the name.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 4

doc.: IEEE 802.11-04/0351r0

Submission

What does Webster (real world) say?• Roam

– to go from place to place without purpose or direction – to travel purposefully unhindered through a wide area

• Handoff– to hand (a football) to a nearby teammate on a play

• Handover– to yield control of

• Mobility– Capable of moving or being moved: MOVABLE <a mobile missile launcher>– a: changeable in appearance, mood, or purpose <mobile face>; b: ADAPTABLE, VERSATILE– MIGRATORY– a: characterized by the mixing of social groups; b: having the opportunity for or undergoing a

shift in status within the hierarchical social levels of a society <socially mobile workers>– Marked by the use of vehicles for transportation <mobile warfare>– Of or relating to a mobile

• Transition– a : passage from one state, stage, subject, or place to another; b : a movement, development, or

evolution from one form, stage, or style to another– a : a musical modulation; b : a musical passage leading from one section of a piece to another– an abrupt change in energy state or level (as of an atomic nucleus or a molecule) usually

accompanied by loss or gain of a single quantum of energy

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 5

doc.: IEEE 802.11-04/0351r0

Submission

Terms Used in the Cellular World

• Roaming– Roaming is defined as the ability for a cellular customer to automatically

make & receive voice calls, send & receive data, or access other services when travelling outside the geographical coverage area of the home network, by means of using a visited network.

– Roaming is technically supported by mobility management, authentication and billing procedures. Establishing roaming between network operators is based on - and the commercial terms are contained in - Roaming Agreements.

• Handoff– The process by which the Mobile Telephone Switching Office (MTSO)

passes a cellular phone conversation from one radio frequency in one cell to another radio frequency in another. It is performed so quickly that callers don’t notice.

• Handover– Similar meaning as above

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 6

doc.: IEEE 802.11-04/0351r0

Submission

Reference to “roaming” in 802.11 Standard

• 802.11 2003 edition does make one reference to the word “roaming” in clause A.4.10 (page 380) that seems to have similar meaning to the use of the term roaming in the cellular world, i.e. a change from one regulatory domain (or geographic area) to another.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 7

doc.: IEEE 802.11-04/0351r0

Submission

Terms Used in the 802.11 world• Station Mobility (transition), Page 1.

• Section 5.4.2.1 Mobility types definition:

5.4.2.1 Mobility typesThe three transition types of significance to this standard that describe the mobility of stations within a network are as follows:a) No-transition: In this type, two subclasses that are usually indistinguishable are identified: 1) Static: no motion. 2) Local movement: movement within the PHY range of the communicating STAs [i.e., movement within a basic service area (BSA)].b) BSS-transition: This type is defined as a station movement from one BSS in one ESS to another BSS within the same ESS.c) ESS-transition: This type is defined as station movement from a BSS in one ESS to a BSS in a different ESS. This case is supported only in the sense that the STA may move. Maintenance of upper- layer connections cannot be guaranteed by IEEE 802.11; in fact, disruption of service is likely to occur.

The different association services support the different categories of mobility.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 8

doc.: IEEE 802.11-04/0351r0

Submission

Infrastructure BSS’s and ESS’sESS #1 ESS #2

BSS

BSS

BSS

BSS BSS

BSS

BSS

Yes, this BSS is part of ESS #1, even though the coverage area

does not overlap with other BSSs that are part of ESS#1.

An ESS is a logical entity.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 9

doc.: IEEE 802.11-04/0351r0

Submission

Mobility TypesESS #1 ESS #2

MU

MU

MU

MU

IBSS

MU “No Transition”

“BSS-transition”

“ESS-transition”

Undefined in clause 5.4.2.1, but per clause 10.3.10.1 this is a change from one type of BSS

to another type of BSS.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 10

doc.: IEEE 802.11-04/0351r0

Submission

Scope of Proposed Project

“Enhance the 802.11 Medium Access Control (MAC) layer to minimize or eliminate the amount of time data connectivity between the roaming STA and the DS is absent during a roam, limited to the state necessary for the operation of the MAC. This PAR will apply only to the STA-AP state within the same ESS, and will not apply to the IBSS case. Security must not be decreased as a result of the enhancement. Timing criteria and timing conditions will be defined by the Task Group.”

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 11

doc.: IEEE 802.11-04/0351r0

Submission

Mobility Types Within ScopeESS #1 ESS #2

MU

MU

MU

MU

IBSS

MU

“BSS-transition”This is the only

mobility type within scope of

the PAR.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 12

doc.: IEEE 802.11-04/0351r0

Submission

Possible Names

• Fast Roaming – “Roaming” is not well defined and may be too broad of a term.

• Fast Intra-ESS Transition – The term “Intra-ESS Transition” includes the No-transition mobility type, which is out of scope.

• Fast BSS-Transition – The term “BSS-Transition” is a mobility type already defined in clause 5.4.2.1 and is well aligned with the scope.

• Fast Inter-BSS-Transition – The term “BSS-Transition’ is a mobility type already defined in clause 5.4.2.1 and is well aligned with the scope. The term “inter” makes it clearer that mobility between BSSs is being addressed.

• Fast Inter-ESS Transition – This mobility type is out of scope.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 13

doc.: IEEE 802.11-04/0351r0

Submission

Proposed Change #1

• Title of Document:Draft Amendment to STANDARD for Information Technology-Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements-Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Amendment __: Fast Roaming BSS-Transition

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 14

doc.: IEEE 802.11-04/0351r0

Submission

Proposed Change #2

• Scope of proposed project: Enhance the 802.11 Medium Access Control (MAC) layer to minimize or eliminate the amount of time data connectivity between the roaming STA and the DS is absent during a roam BSS-transition, limited to the state necessary for the operation of the MAC. This PAR will apply only to the STA-AP state within the same ESS, and will not apply to the IBSS case. Security must not be decreased as a result of the enhancement. Timing criteria and timing conditions will be defined by the Task Group.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 15

doc.: IEEE 802.11-04/0351r0

Submission

Alignment with 802.21 WG

• Those changes will help to align the name of the 802.11 Task Group with the naming of the 802.21 Working Group.

March 2004

Haixiang He, Darwin Engwer, Nortel Networks

Slide 16

doc.: IEEE 802.11-04/0351r0

Submission

Straw Poll

• Which name do you prefer?– Fast Roaming– Fast BSS-Transition– Fast Inter-BSS-Transition– others?– Fast Food