Initial Response to Telecom Wireless RFP telecom000501

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Initial Response to Telecom Wireless RFP telecom000501

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1 NOKIA 2000 TELECOM-00-06-03.PPT/ 13.6.2000 / Kimmo Raatikainen ... Nokia Research Center (Department of Computer Science, University of Helsinki) ... – PowerPoint PPT presentation

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Title: Initial Response to Telecom Wireless RFP telecom000501

1
Initial Response to Telecom Wireless
RFPtelecom/00-05-01

Kimmo Raatikainen
Nokia Research Center
(Department of Computer Science, University of
Helsinki)

2
Presentation Outline - 1/2

Prelude
Contact persons, response to RFP, design
rationale
Architectural Framework
usage framework, wCORBA extensions
GIOP mappings
onto UDP, onto WAP Wireless Transaction Protocol
(WTP)
Wireless CORBA Extensions
Location Transparent IOR, Bootstrapping the
terminal, Initial access, Interface to visited
NS, Home Location Register
Handoff and Access Recovery

3
Presentation Outline - 2/2

Issues to be discussed
Notification Service Mobility Events
Interoperable Naming Service
Messaging Service
Other ORB Services Generic Invitation Service
Homeless Terminals
Conformance Points
Conclusions

4
Contact Persons

Nokia Kimmo Raatikainen
kimmo.raatikainen_at_nokia.com
Vertel Shahzad Aslam-Mir
sam-aslam-mir_at_vertel.com
Sonera Jouni Korhonen
jouni.korhonen_at_sonera.com
University of Helsinki Kimmo Raatikainen
kimmo.raatikainen_at_cs.helsinki.fi

5
RFP Requirements - 1/2

Architectural framework
GIOP mapping onto Internet transport protocol
(TCP or UDP) over wireless links
Mechanism that hides from CORBA clients the
mobility of terminals on which CORBA servers are
running
Mechanism for initial access to a new mobility
domain
Mechanism for finding the necessary basic set of
CORBA services in mobility domain
Mechanism for advertising CORBA services
available on a mobile terminal
Mechanism for handoff between mobility domain
All these requirements are addressed.

6
RFP Requirements -2/2

This response proposes a GIOP mapping onto WAP
Wireless Transaction Protocol WTP
This response discusses usage of
Notification Service,
Interoperable Naming Service, and
Messaging Service.
The response also discusses usage of other ORB
Services.

7
Design rationale

Design is based on the results from the EC/ACTS
project DOLMEN
DOLMEN specified and implemented a prototype
based on CORBA 2.0
This response takes advantage of CORBA 2.3
features
Target is a general framework for mobility - not
only terminal mobility but an object group
mobility
some of the complexity may be removed if only
terminal mobility would be addressed (one object
group in a terminal)
Wireless access without (ORB-level) mobility as a
well-defined subset serves also for UDP-mapping
in WANs
Reuse of IETF defined session protocol

8
Architectural Framework
9
(No Transcript)
10
Assumptions - 1/2

In order to exploit all features specified in
this proposal CORBA applications (or generic ORB
application libraries) on mobile terminals need
to be aware of mobility.
Each terminal is an ORB domain of its own.
Terminals attach to other ORB domains through an
access node that implements a low-level
interoperability bridge called Wireless Access
Bridge (WAB)
A Wireless Access Bridge may support ES-IOPs for
mobile terminals.

11
Assumptions - 2/2

A terminal may have a home domain, in which a
Home Location Register interface is implemented.
The Home Location Register provides the means to
find the Wireless Access Bridge to which the
terminal is currently attached.
A Wireless Access Bridge may provide a temporary
HLR for "homeless" terminals

12
Domain Definition

RFP mobility domain to denote a domain that
allows access from mobile terminals and provides
them ability to use and to offer CORBA-based
services is sufficient.
We do not use the term mobility domain.
Instead, we use the term visited domain in a
similar sense.
A visited domain consists of one Wireless Access
Bridge and a set of CORBA Services that are
available through a Wireless Access Bridge.
It should be noted that two or more Wireless
Access Bridge can share the set of CORBA Services
available through them.
Therefore, a single instance of a CORBA Service
can be available through several visited domains.

13
Bridge associations
14
Wireless CORBA Extensions
15
Terminal domain
16
Mobile Terminal Bridge

terminal bootstrap
initial access
handoff
access recovery
GIOP/UDP mapping
optionally the GIOP/WAP mapping

17
ORB Service Agent

provides the means of transparently accessing
Naming Service and other ORB services in the
visited domain.
The binding of names into the Naming Service in
the visited domain that are automatically rebind
to the Naming Service in the new visited domain
after a handoff.
The binding of names into the Naming Service in
the home domain the IORs of which are
automatically updated domain after a handoff.
For the other ORB services the handoff is only
semi-automatic.
The old references are stalled but new references
need explicit involvement of the application.

18
Mobility Event Supplier

mandatory part of the proposed technology in the
terminal domain
generates notifications of
handoffs,
connectivity drops, and
connectivity recoveries.
an optional feature in the visited domains

19
Visited domain
20
Wireless Access Bridge

Counterpart of the Mobile Terminal Bridge in the
access network domain.
implements the support of the mandatory parts of
the mobile terminal including support
initial access,
visited domain services,
location transparent IORs,
ORB Service Agent,
handoff and
access recovery.

21
Home domain
22
Home Location Register

provides the means of keeping track of the
current location
the Wireless Access Bridge in current visited
domain.
provides the means of accessing the ORB Services
in the home domain, even if the access is through
a visited domain.
The HLR interface also provides the means of
updating the references available through the
Naming Service in the home domain.
May support paging
Must have the paging method
but it can raise exception PagingNotSupported

23
GIOP mappings

onto UDP based on IETF Stream (aka Simple)
Control Transmission Protocol (SCTP) proposal
onto WAP Wireless Transaction Protocol Class 1

24
Wireless IOP

GIOP mapping onto UDP
UDP is an unreliable connectionless datagram
(message-based) transport service
a protocol layer is needed between GIOP and UDP
to provide required reliability and mobility
support
GIOP Session Protocol (GSP) provides
reliability,
fragmentation,
error detection,
flow and congestion control,
resistance to flooding and masquerade attacks.

25
GIOP-UDP mapping
26
GIOP-UDP mapping Design rationale

Statefull session protocol is needed
Several session protocol specifications are
available
Stream (aka Simple) Control Transmission Protocol
(SCTP) most prominent
better alternatives are wellcome
GIOP Session Protocol follows the design of the
SCTP
some differences in fields of protocol messages
some additional chunk types to support handoffs
and access recovery
Nevertheless, the protocols are quite close to
each other so that a high degree of reuse in
implementing those two protocols is expected.

27
GIOP Session Protocol - 1

A modified SCTP
draft-ietf-sigtran-sctp-09.txt (status IESG last
call)
Reliability
message numbering
error detection thru Adler-32
Selective ACKs
Fragmentation
WIOP message size should be (at most) MTU

28
GIOP Session Protocol - 2

Flow/congestion control
needed to bound GSP control message delays
needed to bound number of datagrams lost during
handoffs
In SCTP TCP-like control mechanism
In IETF Endpoint Congestion Management WG just
started Ratebased congestion control
to be selected in the revised submission

29
GSP Messages - 1

From SCTP
INIT, INIT ACK
Selective Acknowledgement
Heartbeat Request, Heartbeat ACK
ABORT
SHUTDOWN, SHUTDOWN ACK
Operation Error
State Cookie, Cookie ACK
Payload Data

30
GSP Messages - 2

AccessRequest, AccessRequestACK
AccessRecoveryRequest, AccessRecoveryRequestACK
AccessRequestReply, AccessRequestReplyACK
AccessRecoveryReply, AccessRecoveryReplyACK
HandoffRequest, HandoffRequestACK
Synchronize, SynchronizeACK
Tunneled Data
Segmented Chunk

31
GSP datagram format
32
GSP Common Header Format
Chunk Field Description
33
INIT Message
34
Access Request Message
35
Segmented Chunk

to encapsulate a segment of a chunk that does not
fit into a single GSP datagram
Most chunks are small, but
Access Request, Access Reply,
Access Recovery Request, and
Access Recovery Request Reply may be quite long
The receiver must obtain all partial chunks
before acknowledging the chunk.
If the beginning chunk (that contains the Chunk
ID) is missing, all partial chunks MUST be
silently discarded.
If middle parts or the end part is missing, the
receiver MAY use negative acknowledgement if the
chunk type has the corresponding Acknowledgement
chunk.

36
GIOP - WAP WTP mapping

The Wireless Transaction Protocol is designed for
request/reply applications.
WTP runs on top of a datagram service, called
Wireless Datagram Protocol (WDP), and optionally
it may use a security service, called Wireless
Transport Layer Security (WTLS).
If IP is the bearer, then WDP is UDP
WTP Class 1 transactions provide a reliable
datagram service
The reliability provided by WAP WTP Class 1 is
sufficient for GIOP messaging.
A GIOP message in the CDR format is transmitted
in an Invoke PDU or in Segmented Invoke PDUs of
WAP WTP.
The SAR functionality is needed for the GIOP-WTP
mapping

37
Wireless CORBA Extensions

Location Transparent IOR
Bootstrapping the terminal
Initial Acces
ORB Service Agent
WAB Interface to Naming Service
Home Location Register

38
Location Transparent IOR

One of the mandatory requirements in the RFP was
to specify mechanisms that hides mobility of
terminals on which CORBA servers are running from
CORBA clients
This can be done by introducing a location
transparent IOR
A new IOR component called TAG_MOBILE_IOP
struct
version giop_version
string HLR_host
unsigned short HLR_port
sequence ltoctetgt HLR_object_key
sequence ltoctetgt object_group_id //
terminal_id
sequence ltoctetgt object_key // object at
terminal

39
Object Reference Translation

When a local object reference is passed from a
mobile terminal through the Mobile Terminal
Bridge, it is converted into WIOPIOR format.
module WIOP
struct IOR
string type_id
sequence ltoctetgt object_group_id
sequence ltoctetgt object_key
When a Wireless Access Bridge receives an object
reference in WIOPIOR format, it converts it
into IOPIOR format.
In the profile body the WAB puts its own host,
port and object_key as well as the TAG_MOBILE_IOP
component.

40
Updating Object Reference

If a Wireless Access Bridge gets an invocation to
an object on a mobile terminal to which it does
not have an association, then the WAB queries the
current WAB from the Home Location Register.
The WAB either
replies with LOCATION_FORWARD to the requester or
forwards the invocation to the current WAB.
If the invocation is forwarded, then the WAB uses
LOCATION_FORWARD_PERM in the reply.

41
Bootstrapping the terminal - 1/2

the usual ORB initialization (see Section 4.6-7
in CORBA V2.3)
mobile specific initialization
ObjectIdList list_wireless_access_services ()
Object resolve_wireless_access_references (
in ObjectId identifier
) raises (InvalidName)
Initial reference obtained
MobilityEventSupplier (local reference),
HomeLocationRegister (IOPIOR), and
ORBServiceAgent (local reference).

42
Bootstrapping the terminal - 2/2

the mobile terminal needs to get the
object_group_id identifying the terminal, and
which is also known in the home location
register
ObjectGroupId resolve_object_group_name (
in string object_group_name
) raises (InvalidName)
Open Issue Do we need MTB_init similar to
ORB_init?
Most probably not!
Initialization of MTB from an initialization file
much more simple and robust.

43
Initial Access

It is not always feasible to maintain
connectivity all the time.
MTB provides operations to establish and release
connectivity
void connect (
in ObjectGroupId object_group_id,
in Object HLR_reference,
in sequence ltoctetgt location_update_credentials,
in long timeout
) raises (AccessDinied, RequestTimeout)
void disconnect (
in ObjectGroupId object_group_id,
in Object HLR_reference,
in sequence ltoctetgt location_update_credentials,
in long timeout
) raises (AccessDinied, RequestTimeout)

44
Establishing GIOP Session - 1/3

Several CORBA applications may simultaneously be
running
Only one GIOP Session between the MTB and WAB.
The GIOP Session is shared by all applications
running on the terminal.
The Wireless Access Bridge maintains mapping
between the object_group_id and UDP endpoint of
the Mobile Terminal Bridge.

45
Establishing GIOP Session - 2/3
MTB
WAB
HLR
connect
INIT
INIT ACK
COOKIE
ACCESS REQ
COOKIE ACK
ACCESS REQ ACK
update_location
ACCESS REP
ACCESS REP ACK
TerminalHandoffEvent
HandoffArrivalEvent
46
Establishing GIOP Session - 3/3

If the acknowledgement does not arrive in time,
then the corresponding message is resent
according the (implementation dependent)
retransmission policy.
The peer MUST interpret duplicate messages as
lost acknowledgement and re-send the
corresponding acknowledgment.
The MTB and WAB MAY use the HEARTBEAT message to
probe the connectivity.
The ABORT message MUST be sent, when the initial
access procedure is terminated.

47
Closing GIOP Session

When an application invokes the disconnect
operation
then if no other application uses the same
object_group_id
MTB clears the current WAB information in the
HLR, which in turn unbinds the names in the
Naming Service
the WAB unbinds names from the Naming Service
WAB generates HandoffDepartureEvent
If no other application uses the GIOP Session,
then the MTB sends the SHUTDOWN message to the
WAB
which replies with the SHUTDOWN ACK message.

48
ORB Service Agent Interface - 1/3

void register_object_group (
in string object_group_name,
in Object HLR_reference,
out ObjectGroupId object_group_id,
out sequenceltoctetgt location_update_credentials,
in sequenceltoctetgt register_credentials
) raises (NameNotUnique, NoAccess,
AccessViolation)
void unregister_object_group (
in ObjectGroupId object_group_id,
in Object HLR_reference,
in sequenceltoctetgt register_credentials
) raises (UnknownObjectGroupID, NoAccess,
AccessViolation)

49
ORB Service Agent Interface - 2/3

ObjectIdList list_visited_domain_services (
) raises (NoAccess)
Object resolve_visited_domain_references (
in ObjectId identifier
) raises(InvalidName)
ObjectIdList list_home_domain_services (
) raises (NoAccess)
Object resolve_home_domain_references (
in ObjectId identifier
) raises(InvalidName)

50
ORB Service Agent Interface - 3/3

Interface to Naming Service in Visited and Home
Domains
At least the following operations should be
provided
ltdomaingt_bind,
ltdomaingt_resolve,
ltdomaingt_unbind
where ltdomaingt is either visited_domain or
home_domain.

51
WAB Interface to Naming Service

Used by ORB Service Agent
void visited_domain_bind (
in Name n,
in Object obj
) raises (NotFound, CannotProceed, InvalidName,
AlreadyBound)
Object visited_domain_resolve (
in Name n
) raises (NotFound, CannotProceed, InvalidName)
void visited_domain_unbind (
in Name n
) raises (NotFound, CannotProceed, InvalidName)

52
Home Location Register - 1/4

void update_location (
in ObjectGroupId object_group_id,
in string host, // new access bridge
in unsigned short port,
in sequenceltoctetgt location_update_credentials,
) raises (UnknownObjectGroupID, AccessViolation,
IllegalTargetBridge)
void query_location (
in ObjectGroupId object_group_id,
out string host,
out unsigned short port
) raises (UnknownObjectGroupID,
UnknownObjectGroupLocation)

53
Home Location Register - 2/4

void register_object_group (
in string object_group_name,
out ObjectGroupId object_group_id,
out sequenceltoctetgt location_update_credentials,
in sequenceltoctetgt register_credentials
) raises (NameNotUnique, AccessViolation)
void unregister_object_group (
in ObjectGroupId object_group_id,
in sequenceltoctetgt register_credentials
) raises (UnknownObjectGroupID, AccessViolation)

54
Home Location Register - 3/4

void paging (
in string object_group_name,
in long timeout
) raises (PagingNotSupported, ObjectGroupNotFound,
RequestTimeout)
ObjectIdList list_home_domain_services ()
Object resolve_home_domain_references (
in ObjectId identifier
) raises(InvalidName)

55
Home Location Register - 4/4

void home_domain_bind (
in Name n,
in Object obj
) raises (NotFound, CannotProceed, InvalidName,
AlreadyBound)
Object home_domain_resolve (
in Name n
) raises (NotFound, CannotProceed, InvalidName)
void home_domain_unbind (
in Name n
) raises (NotFound, CannotProceed, InvalidName)

56
Handoff

Handoff in general
Network Initiated Handoff
Terminal Initiated Handoff
Access Recovery

57
Handoff and Access Recovery - 1/3

Handoff consists of three distinct phases
the information gathering phase,
the decision phase, and
the execution phase.
Bridge handoff is a part of the execution phase
in cases, where the mobile terminal moves from
one bridging domain to another.
There are two different cases of handoff
the backward handoff and
the forward handoff (access recovery).

58
Handoff and Access Recovery - 2/3

The backward one is the normal case
The forward one is performed
as a location update
in order to re-establish communication after a
sudden loss of connectivity.
In the response we use
the term handoff to mean the backward handoff and
the term access recovery.
The handoff may be network initiated or terminal
initiated.
The access recovery is always terminal initiated.

59
Handoff and Access Recovery - 3/3

Create a new bridge association.
Transfer the responsibility from the old WAB to
the new WAB.
Convert the old bridge association to the
secondary (tunnelled) status.
Update Home Location Entries of the object groups
on the terminal.
Rebind the entries in the Naming Service in the
home domain.
Unbind the names in the Naming Service in the old
visited domain.
Bind the names into the Naming Service in the new
visited domain.
Generate the corresponding mobility events in the
terminal domain as well as in the old and new
visited domains.
Obtain references to services in the new visited
domain and mark as staled those in the old
visited domain.

60
Handoff initiation

Wireless Access Bridge
oneway do_handoff(
in sequenceltoctetgt session_id,
in Object new_wireless_access_bridge,
in Object status_callback_target,
in string status_callback_op_name
)
Mobile Terminal Bridge
oneway propose_handoff(
in sequenceltoctetgt new_wireless_access_bridge_add
ress,
in Object status_callback_target,
in string status_callback_op_name
)

61
Network Initiated Handoff - 1/2
old WAB
new WAB
MTB
do_handoff
handoff_request
HANDOFF REQ
Store info Do preparations
HANDOFF ACK
SHUTDOWN
SHUTDOWN ACK
HandoffDepartureEvent
Unbind names from NS
INIT
INIT ACK
COOKIE
62
Network Initiated Handoff - 2/2
new WAB
HLR
MTB
ACCESS REQ
COOKIE ACK
ACCESS REQ ACK
update_location
ACCESS REP
ACCESS REP ACK
rebind names in NS
TerminalHandoffEvent
HandoffArrivalEvent
handoff_completed
bind names to NS
old WAB
63
Handoff methods

// Called by the old WAB at the new WAB
void handoff_request(
in sequenceltoctetgt session_id,
in SessionState old_wab_state,
in sequenceltoctetgt old_wab_tunnel, // TCP/IP
endpoint
out sequenceltoctetgt new_terminal_access_point
) raises (HandoffFailure)
// Called by the new WAB at the old WAB
void handoff_completed(
in sequenceltoctetgt old_session_id,
in sequenceltoctetgt new_session_id,
in HandoffStatus status
)

64
Terminal Initiated Handoff - 1/3

Optional feature at MTB, must be supported by WAB
When the propose_handoff operation in the Mobile
Terminal Bridge is invoked, then the terminal
starts the terminal initiated handoff procedure.
The terminal initiated Handoff procedure requires
that the terminal can establish connectivity to
the new Wireless Access Bridge before releasing
the connectivity to the old Wireless Access
Bridge.
If this cannot be done, then the terminal
initiated handoff must be done using the access
recovery mechanism
The Mobile Terminal Bridge sends an ABORT message
to the old WAB and
then carries out the access recovery to the new
WAB.

65
Terminal Initiated Handoff - 2/3
new WAB
MTB
propose_handoff
INIT
INIT ACK
COOKIE
ACCESS REQ
COOKIE ACK
ACCESS REQ ACK
HANDOFF REQ
HANDOFF ACK
SHUTDOWN
old WAB
66
Terminal Initiated Handoff - 3/3
old WAB
new WAB
HLR
MTB
SHUTDOWN ACK
handoff_request
Store info
update_location
HandoffDepartureEvent
Unbind names from NS
rebind names in NS
ACCESS REP
ACCESS REP ACK
HandoffArrivalEvent
TerminalHandoffEvent
handoff_completed
bind names to NS
67
Access Recovery - 1/4
MTB
WAB
TerminalDropoutEvent
INIT
INIT ACK
COOKIE
RECOVERY REQ
COOKIE ACK
RECOVERY ACK
68
Access Recovery - 2/4
MTB
old WAB
SYNC
SYNC ACK
SYNC
SYNC ACK
Missing data and acknowledgements
AccessRecoveryEvent if AccessDropoutEvent
delivered
TerminalRecoveryEvent
69
Access Recovery - 3/4
new WAB
old WAB
HLR
MTB
recovery_request
Store info
update_location
RECOVERY REP
rebind names in NS
RECOVERY ACK
SYNC
SYNC ACK
SYNC
SYNC
SYNC ACK
SYNC ACK
Missing data and acknowledgements
Missing data and acknowledgements
70
Access Recovery - 4/4
new WAB
old WAB
MTB
recovery_completed
HandoffDeparturelEvent
Unbind names from NS
TerminalHandoffEvent
HandoffArrivalEvent
bind names to NS
71
Access Recovery Methods

// Called by the new WAB at the old WAB
void recovery_request(
in sequenceltoctetgt session_id,
out SessionState old_wab_state,
out sequenceltoctetgt old_wab_tunnel // TCP/IP
endpoint
out sequenceltoctetgt new_terminal_access_point
) raises (HandoffFailure)
// Called by the new WAB at the old WAB
void recovery_completed(
in sequenceltoctetgt old_session_id,
out sequenceltoctetgt new_session_id,
in HandoffStatus status
)

72
Issues to be discussed

Use of Notification Service
Use of Interoperable Naming Service
Use of Messaging Service
Use of generic ORB Services

73
Mobility Events - 1/3
74
Mobility Events - 2/3

module Mobility
struct TerminalHandoffEvent
DomainId new_visited_domain
struct HandoffDepartureEvent
TerminalName moving_terminal
DomainId new_visited_domain
struct HandoffArrivalEvent
TerminalName moving_terminal
DomainId old_visited_domain

75
Mobility Events - 3/3

struct TerminalDropoutEvent
struct TerminalRecoveryEvent
struct AccessDropoutEvent
TerminalName dropped_terminal
struct AccessRecoveryEvent
TerminalName dropped_terminal

76
Use of Interoperable Naming Service - 1/2

This specification does not affect the
specification of Interoperable Naming Service.
The ORB Service Agent provides operations so that
the applications on a mobile terminal need only
once bind a name into the Naming Service in a
visited domain.
The ORB Service Agent together with the Wireless
Access Bridge moves the name bindings from the
Naming Service in the old visited domain to that
in the new visited domain during the handoff
procedure.
The WAB also takes care that entries in the
Naming Service are removed if the terminal
disappears and does not re-appear in an
implementation depend time-interval.

77
Use of Interoperable Naming Service - 2/2

The object references, the names of which are
bound into the Naming Service in the home domain
through the ORB Service Agent, are automatically
updated during the handoff procedure.
Naming Conventions
recommendation
mobile_terminal/lthome_domain_namegt/ltterminal_namegt
/ltobject_namegt

78
Use of Messaging Service

This proposal does not give any specific uses for
Messaging Service, nor is use of Messaging
Service in any way affected by the proposed
technology.
However, it is possible to reduce the amount of
messages sent with Messaging Service somewhat
with a simple optimization.
Since the Wireless Access Bridges used by the
mobile terminal are better informed on the
terminal's whereabouts and connectivity,
it would be beneficial to implement Messaging
Router functionality in the WAB.

79
Use of other ORB Services

The mobile terminal will also need to access
CORBAservices in other ORB domains.
ORB Service Agent is provided for use by the
mobile terminal.
The ORB Service Agent provides facilities for the
mobile terminal to query and access available
services in both the visited domain and the
terminal's home domain.
In case of handoff, the ORB Service Agent
automatically receives services available in the
new visited domain.
However, an application need to resolve object
references.

80
Generic Invitation Service - 1/2

Although not requested in the RFP, this proposal
specifies a generic invitation server.
Its objective is to provide an interface that
allows objects in other domains to contact the
terminal.
It is recommended that this interface is bound to
the Naming Service in the visited and home
domains.
When an application wants to contact an
application on the mobile terminal, then it
invokes the invite operation.

81
Generic Invitation Service - 2/2

enum InvitationStatus
INVITATION_ACCEPTED, INVITATION_REJECTED
interface InvitationServer
void invite(
in string invating_party, // name of user
in string invating_application, // name of
application
out InivitationStatus status,
out string reply_message,
out Object peer_object)

82
Homeless Terminals
83
Homeless Terminals

A "homeless terminal" is a terminal that does not
have a home domain and hence an entry in a Home
Location Register.
In the current specification the Home Location
Register provides the means for a domain to
authenticate the visiting terminal
If the terminal does not have an HLR entry, then
it is impossible to do ORB-level authentication
before the Wireless Access Bridge accepts the
establishment of a GIOP Session.
A "homeless terminal" MUST use NIL as its HLR
reference.
A Wireless Access Bridge MAY reject an access
request with NIL as the HLR reference.

84
Conformance Points

Wireless Access
Terminal Mob ility
Optional features

85
Wireless Access Conformance Point

Initial access,
access recovery, and
either GIOP/UDP mapping
a subset of GIOP Session Protocol
or GIOP/WAP WTP mapping.

86
Terminal Mobility Conformance Point - 1/4

In the terminal domain
- terminal bootstrap,
- initial access,
- access recovery,
- network initiated handoff,
- ORB Service Agent interface,
- mobility events, and
- GIOP/UDP mapping.

87
Terminal Mobility Conformance Point - 2/4

In the visited domain
- Initial access,
- access recovery,
- network initiated handoff,
- terminal initiated handoff,
- support of ORB Service Agent, and
- GIOP/UDP mapping.

88
Terminal Mobility Conformance Point - 3/4

In the home domain
- Home Location Register interface.
- Obs. HLR must implement the paging function.
If a paging is not supported, then the paging
operation MUST raise the exception
PagingNotSupported.

89
Terminal Mobility Conformance Point - 4/4