NETLMM Applicability Draft (Summary)

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NETLMM Applicability Draft(Summary)

• 28 Sep. 2006

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Purpose of the Draft

• General
• The initial purpose is to provide the
  applicability analysis for WG which makes base
  protocol standardization be easier
• Illustrate how NETLMM works under a MN-AR IF,
  i.e. LTE access
• The draft aims to illustrate the NETLMM
  applicability to the current 3GPP SAE
  architecture
• clarify what parameters are required to activate
  NETLMM routing path establishment/modify/delete
• Notes
• May need to update the detail when some key
  points for NETLMM applicability, e.g. detail
  handover signaling flow, has been fixed

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Table of Contents

• Introduction
• Terminology
• Overview of the 3GPP SAE/LTE network
• 3.1. Simplified SAE Network Architecture
• 3.2. Network Attachment
• 3.3. Inter MME/UPE Mobility within the LTE access
  system
• NETLMM Application for SAE network with LTE
  access system
• 4.1. NETLMM function entity configuration
• 4.2. Network Attachment with NETLMM
• 4.3. Inter UPE mobility by NETLMM
• Conclusion
• Security Considerations
• Acknowledgements
• References

ID management would be described
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3.1. SAE Network Architecture for Mobility
Management
Base Line Architecture Figure

• Architecture figure is focused on LTE access
  accommodation
• MME/UPE is assumed to be logically separated, but
  for now we regard they are physically collocated.
• In the document, only single anchor will be
  illustrated in stead of 3GPP anchor and SAE
  anchor, i.e. LTE anchor
• Note that LTE anchor is a non-standard term and
  used only for explanation purpose in this draft.

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GPRS ID management

• At GGSN,
• GGSN located at home network, except the case of
  local breakout
• GGSN maintains IMSI as a key for PDP context at
  GGSN
• At SGSN,
• SGSN located at visited network
• SGSN allocates TMSI created from IMSI
• TMSI needs to be updated every time SGSN changes
  (P-TMSI Reallocation Procedure between SGSN and
  MN)
• SGSN maintains IMSI as the main reference key for
  PDP context at SGSN

IMSI is used as the main key for PDP context at
both GSGN and SGSN
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SAE ID management (under discussion)

• At MME,
• Authentication, authorization (PLMN, TA) and key
  management
• Working With HSS
• Ciphering/integrity termination for signaling
• S1 C-Plan termination
• S1 U-Plan tunnel termination
• (L2 tunnel ?? L3 tunnel)
• Management and allocation of temporary user
  identities
• TMSI like identifier allocation, similar to SGSN

IMSI would be necessary to handle the mobility
between MME/UPEs ? IMSI seems to be a appropriate
identifier for NETLMM used for S5 IF
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Network Attachment
Figure in TR23.882
Application of NETLMM signaling (Location Reg/Ack)

• This procedure is under discussion (one of the
  alternatives)
• But step 7 and 9, target of NETLMM, exists for
  every alternatives
• Subscriber data transactions with HSS (step4,5)
  can be combined with steps 3,6

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Inter MME/UPE Mobility within the LTE access
system
Figure in TR23.882
Application of NETLMM signaling (Location Reg/Ack)

• This procedure is under discussion (one of the
  alternatives)
• But step 11, target of NETLMM, exists for every
  alternatives
• It is not yet discussed how to handle temporary
  identifier when MME/UPE changes

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Parameters Exchange(Network Attachment)
NM ID for NETLMM
(IMSI, TMSI)
Could be in step 4
(APN, IASA address, MN prefix)
(IMSI, MME/UPE address, IASA address, MN prefix)
(IMSI, MME/UPE address, IASA address)

• IMSI is assumed to be MN ID for NETLMM
• In above, MN prefix is provided by HSS
• IASA may provide MN prefix, but then APN info
  shall be sent in NETLMM message

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Parameters Exchange(Inter MME/UPE Mobility
within the LTE access system)
MME/UPE can find MN context including MN ID
(IMSI) by info in step3
(IMSI, IASA address, MN Prefix)
(IMSI, MME/UPE address, IASA address, MN Prefix)
(IMSI, MME/UPE address, IASA address)

• This procedure is under discussion (one of the
  alternatives)
• But step 11, target of NETLMM, exists for every
  alternatives
• Location Deregistration is not required in this
  signaling flow
• Not decided yet. Detail is under discussion in
  3GPP
• The function to delete old MME/UPE info is
  provided by context transfer IF
• Should be say the use of Location Deregistration
  is optional ?
• Depends on the target system can do it by its
  specific system or not.

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Bearer Management in 3G(discussion for multiple
Prefix to a MN ID)

• 28 Sep. 2006

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What is done in GPRS

• MS can initiate the activation, modification, and
  deactivation functions at any time for a PDP
  context
• MN can have multiple PDP contexts, for instance,
• Register IMS for VoIP (the bearer for VoIP call
  with IP-1)
• MN starts web access (establish new bearer to
  access PDN-A with IP-2)
• Connects to corporate network (establish new
  bearer to access PDN-B, corporate network, with
  IP-3)

It is possible MN to establish PDP context,
similar to NETLMM tunnel, upon necessary
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Bearer Management in SAE

• SAE is working on multiple PDN access
• Same as what can be done in GPRS
• The solution is under discussion
• IASA may connect to multiple PDN
• For NETLMM, it means different prefixes are
  allocated to a single MN
• Similar to GPRS, it would be required to
  activate, modify, and deactivate a connection to
  PDN for efficient network resource usage
• Some connection, such as default bearer, would be
  kept as long as the MN is attached to the
  network.

Considering the applicability, it is necessary
function to establish, modity, and delete one
NETLMM tunnel form multiple ones