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Software Patent Abstract
Method and system of network management and protocol software architectures
for mobile broadband wireless networks. One embodiment of the software
architecture employs a proxy Simple Network Management Protocol
(SNMP) agent at a base station in the network. The proxy SNMP agent
communicates with an SNMP manager at a network management system
(NMS) using SNMP messages to send Management Information Base (MIB)
objects between the NMS and the base station. The proxy SNMP agent
communicates with a mobile subscriber station (MSS) using media
access control (MAC) messages. The protocol software architecture
further includes a management plane service access point (SAP) and
a control plane SAP deployed in the MSS. The architecture enables
specific parameters corresponding to dynamic service flows and Quality
of Service to be retrieved from and written to an MSS using proxy
SNMP agents at the base stations.
Software Patent Claims
What is claimed is:
1. A software architecture for a broadband wireless access (BWA)
network, comprising: a network management system (NMS), including
a Simple Network Management Protocol (SNMP) manager; a plurality
of proxy SNMP agents, each proxy SNMP agent implemented at a respective
base station (BS) in the BWA network, each SNMP proxy agent enabled
to communicate with the SNMP manager via SNMP messages encapsulating
Management Information Base (MIB) objects and enabled to communicate
with a mobile subscriber station (MSS) via a management channel,
an SNMP proxy agent further enabled to extract MIB objects encapsulated
in SNMP messages received from the SNMP manager and to generate
and send messages to an MSS via the management channel containing
parameters corresponding to the MIB objects that are extracted;
and a service database, to store service flow and associated quality
of service information pertaining to the MSS, wherein the SNMP manager
generates the MIB objects in response to the service flow and associated
quality of service information to reserve a network resource included
in the MSS.
2. The software architecture of claim 1, further comprising: a
management plane service access point (SAP), implemented in an MSS,
the management plane SAP supporting communication between management
plane entities in the MSS and the proxy SNMP agent via management
MAC (media access control) messages sent via the management channel.
3. The software architecture of claim 1, further comprising: a
control plane service access point (SAP), implemented in an MSS,
the control plane SAP supporting communication between control and/or
data plane components in the MSS and the proxy SNMP agent via control
MAC (media access control) messages sent via the management channel.
4. The software architecture of claim 1, further comprising: a
network plane service access point (SAP), to support communication
between the network management system and the base stations using
an Internet protocol (IP) transport over which SNMP messages may
be sent between a proxy SNMP agent and the SNMP manager.
5. The software architecture of claim 1, wherein the network management
system comprises: an element management system (EMS); and a service
database, linked to the EMS, to store service flow data pertaining
to subscribers of services provided by an operator of the (BWA)
network.
6. The software architecture of claim 1, wherein the proxy SNMP
agent is further enabled to maintain an MIB instance containing
dynamic service flow information pertaining to MSSs currently being
served by the base station on which the proxy SNMP agent is implemented.
7. The software architecture of claim 1, wherein an MSS implements
an Institute of Electrical and Electronic Engineers (IEEE) Std.
802.16-based protocol layering reference model including a data/control
plane and a management plane, and the proxy SNMP agent is enabled
to communicate with each of the data/control plane and the management
plane via the management channel using TLV (Type/Length/Value) encoded
messages.
8. A machine-readable medium to store a plurality of software modules,
including: a Simple Network Management Protocol (SNMP) manager module,
to be implemented in a network management system for a broadband
wireless access (BWA) network; a proxy SNMP agent module, to be
implemented at a base station (BS) in the BWA network, the SNMP
proxy agent enabled to communicate with the SNMP manager via SNMP
messages encapsulating Management Information Base (MIB) objects
and enabled to communicate with a mobile subscriber station (MSS)
via a management channel, the SNMP proxy agent further enabled to
extract MIB objects encapsulated in SNMP messages received from
the SNMP manager and to generate and send messages to an MSS via
the management channel containing parameters corresponding to the
MIB objects that are extracted; and a service database module, to
store service flow and associated quality of service information
pertaining to the MSS, wherein the SNMP manager module generates
the MIB objects in response to the service flow and associated quality
of service information to reserve a network resource included in
the MSS.
9. The machine-readable medium of claim 8, wherein the software
components further include: a management plane service access point
(SAP) module, to be implemented in an MSS, the management plane
SAP module to support communication between management plane entities
in the MSS and the proxy SNMP agent module via management MAC (media
access control) messages sent via the management channel.
10. The machine-readable medium of claim 8, wherein the software
components further include: a control plane service access point
(SAP) module, to be implemented in an MSS, the control plane SAP
module to support communication between control/data plane entities
in the MSS and the proxy SNMP agent module via control MAC (media
access control) messages sent via the management channel.
11. The machine-readable medium of claim 8, wherein the software
components further include: a network plane service access point
(SAP) module, to support communication between the network management
system and the base stations using an Internet protocol (IP) transport
over which SNMP messages may be sent between a proxy SNMP agent
module and the SNMP manager module.
12. The machine-readable medium of claim 8, wherein the software
components further include: an element management system (EMS) module,
including an interface to a service database, the EMS module to
retrieve and store service flow data pertaining to subscribers of
services provided by an operator of the (BWA) network from the service
database.
13. The machine-readable medium of claim 8, wherein the proxy SNMP
agent module is further enabled to maintain an MIB instance containing
dynamic service flow information pertaining to MSSs currently being
served by the base station on which the proxy SNMP agent module
is to be implemented.
14. A method comprising: enabling a network management system (NMS)
for a broadband wireless access (BWA) network to communicate with
a mobile subscriber station (MSS) that accesses the BWA network
via a serving base station (BS) by, instantiating an Simple Network
Management Protocol (SNMP) manager at the NMS, instantiating an
proxy SNMP agent at the serving BS; instantiating a service database
to store service flow and associated quality of service information
pertaining to the MSS; sending Management Information Base (MIB)
objects pertaining to operation of the MSS via SNMP messages in
which the MIB objects are encapsulated, wherein the SNMP manager
generates the MIB objects encapsulated in the SNMP messages in response
to the service flow and associated quality of service information
to reserve a network resource included in the MSS; and sending parameters
corresponding to the MIB objects between the proxy SNMP agent and
the MSS using a management channel.
15. The method of claim 14, further comprising retrieving parameters
from an MSS by performing operations including: sending an SNMP
GetRequest message from the SNMP manager to the proxy SNMP agent,
the GetRequest message containing at least one MIB object identifying
one or more parameters to be retrieved from the MSS; extracting
said at least one MIB object and the one or more parameters from
the SNMP GetRequest message at the proxy SNMP agent; generating
a MAC (media access control) request message identifying the one
or more parameters to be retrieved; sending the MAC request message
to the MSS retrieving the one or more parameters identified by the
MAC request message from the MSS; generating a MAC reply message
containing the one or more parameters that are retrieved; sending
the MAC reply message from the MSS to the proxy SNMP agent; generating
an SNMP Response message including an MIB object containing the
one or more parameters that are retrieved; sending the SNMP Response
message from the SNMP agent to the SNMP manager; and extracting
the parameters from the MIB object contained in the SNMP Response
message.
16. The method of claim 15, wherein the one or more parameters
that are retrieved relate to parameters employed by a management
plane entity of the MSS, and the method further comprises: generating
a management MAC request message identifying the one or more parameters
to be retrieved; sending the management MAC request message to be
received by a management plane service access point (SAP) implemented
on the MSS; retrieving the one or more parameters identified by
the management MAC request message from at least one management
plane entity via the management plane SAP; generating a management
MAC reply message containing the one or more parameters that are
retrieved; sending the management MAC reply message from the management
plane SAP to the proxy SNMP agent.
17. The method of claim 15, wherein the one or more parameters
that are retrieved relate to parameters employed by a control or
data plane component of the MSS, and the method further comprises:
generating a control MAC request message identifying the one or
more parameters to be retrieved; sending the control MAC request
message to be received by a control plane service access point (SAP)
implemented on the MSS; retrieving the one or more parameters identified
by the control MAC request message from at least one control or
data plane component via the control plane SAP; generating a control
MAC reply message containing the one or more parameters that are
retrieved; and sending the control MAC reply message from the control
plane SAP to the proxy SNMP agent.
18. The method of claim 14, further comprising: detecting entry
of an MSS into the WBA network; generating an SNMP trap to the SNMP
manager identifying the MSS; downloading service flow and Quality
of Service (QoS) parameters that are pre-provisioned for the MSS
from the NMS to the serving BS using one or more SNMP messages;
populating an MIB instance at the serving BS with the service flow
and QoS parameters for the MSS; and sending service flow and QoS
parameters to the MSS via the management channel.
19. The method of claim 14, further comprising: populating base
station MIB objects in the MIB instance with base station service
flow and QoS parameters corresponding to current service flows provided
by the serving BS to the MSS; and populating subscriber station
MIB objects in the MIB instance with subscriber station service
flow and QoS parameters employed by the MSS corresponding to the
current service flows provided by the serving BS.
20. The method of claim 14, further comprising: determining that
a hand-over of an air-interface for the MSS is to be handed over
from the serving BS to a target BS; sending an SNMP trap from the
proxy SNMP agent at the serving BS to the SNMP manager; and in response
triggering thereof, downloading service flow and Quality of Service
(QoS) parameters that are pre-provisioned for the MSS from the NMS
to a proxy SNMP agent implemented by the target BS using one or
more SNMP messages; populating an MIB instance at the target BS
with the service flow and QoS parameters for the MSS; and handing
over the air-interface for the MSS to the target BS using the service
flow and QoS parameters that are downloaded from the NMS.
Mobile Phone Patent Description
FIELD OF THE INVENTION
The field of invention relates generally to wireless communication
networks and, more specifically but not exclusively relates to a
method and system of network management software architectures for
mobile broadband wireless networks.
BACKGROUND INFORMATION
IEEE (Institute of Electrical and Electronic Engineers) 802.16
is an emerging suite of air interface standards for combined fixed,
portable and Mobile Broadband Wireless Access (MBWA). Initially
conceived as a radio standard to enable cost-effective last-mile
broadband connectivity to those not served by wired broadband such
as cable or DSL, the specifications are evolving to target a broader
market opportunity for mobile, high-speed broadband applications.
The IEEE 802.16 architecture not only addresses the traditional
"last mile" problem, but also supports nomadic and mobile
clients on the go. The MBWA architecture is being standardized by
the Worldwide Interoperability for Microwave Access (WiMAX) forum
Network Working Group (NWG). For convenience, the terms 802.16 and
WiMAX are used interchangeably throughout this specification to
refer to the IEEE 802.16 suite of air interface standards.
FIG. 1 shows a simplified broadband wireless network with point-to-multipoint
(PMP) cellular-like architecture for operation at both licensed
and licensed-exempt frequency bands typically below 11 GHz. Other
types of architectures (not shown) such as mesh broadband wireless
networks are permissible. A backbone IP (Internet Protocol) network
100 is connected to a broadband wireless network using radio access
nodes (RANs) 102A and 102B. Each RAN is connected via a wired link
such as an optical fiber (depicted as optical fiber links 103A,
103B and 103C) or point-to-point wireless link (not shown) to one
or more radio cells (depicted between RAN 102A or 102B to radio
cells 104A, 104B, and 104C). At the hub of a radio cell is a respective
Base station (BS) 106A, 106B, and 106C. A Base Station system includes
an advanced antenna system (AAS), which is typically located on
top of a radio tower and is used to transmit high-speed data to
multiple subscriber stations (SSs) 108 and mobile subscriber stations
(MSSs) 109 and receive data from the subscriber stations via unidirectional
wireless links 110 (each SS uplink transmission is independent on
the others). More particularly, each SS 108 can access network 100
(via an appropriate BS) using the PHY+MAC (Physical+Media Access
Control) layer features defined by the IEEE P802.16 air-interface
standard. An SS may correspond to a fixed subscriber location (e.g.,
in a home or office), or may correspond to a mobile subscriber who
might access the broadband wireless network via a mobile device
(MSS) such as a personal digital assistant (PDA), laptop computer,
etc.
Transmission of data bursts from network 100 to an SS 108 proceeds
in the following manner. The data bursts such as IP packets or Ethernet
frames forwarded from an appropriate RAN to an appropriate BS within
a given cell. The BS encapsulates the data into IEEE 802.16-2004
data frame format, and then transmits non-line-of-sight (NLOS) data
to each SS 108 using a unidirectional wireless link 110, which is
referred to as a "downlink." Transmission of data from
an SS 108 to network 100 proceeds in the reverse direction. In this
case, the encapsulated data is transmitted from an SS to an appropriate
BS using a unidirectional wireless link referred to as an "uplink."
The data packets are then forwarded to an appropriate RAN, converted
to IP Packets or Ethernet frames, and transmitted henceforth to
a destination node in network 100. Data bursts can be transmitted
using either Frequency-Division-Duplexing (FDD), half-duplex FDD,
or Time-Division-Duplexing (TDD) schemes. In the TDD scheme, both
the uplink and downlink share the same RF channel, but do not transmit
simultaneously, and in the FDD scheme, the uplink and downlink operate
on different RF channels, but the channels are transmitted simultaneously.
Multiple BSs are configured to form a cellular-like wireless network.
A network that utilizes a shared medium requires a mechanism to
efficiently share it. Within each cell, the wireless network architecture
is a two-way PMP, which is a good example of a shared medium; here
the medium is the space (air) through which the radio waves propagate.
The downlink, from the base station (BS) to an SS, operates on a
PMP basis. Provisions within the IEEE 802.16-2004 standard and IEEE
802.16e/D5a draft specification (December, 2004) include a central
BS with AAS within each cell. Such an AAS includes a sectorized
antenna that is capable of handling multiple independent sectors
simultaneously. Under this type of configuration, the operations
of base stations described below may be implemented for each of
the independent sectors, such that multiple co-located base stations
with multiple sector antennas sharing a common controller may be
employed in the network. Within a given frequency channel and antenna
sector, all stations receive the same transmission, or parts thereof.
In the other direction, the subscriber stations share the uplink
to the BS on a demand basis. Depending on the class of service utilized,
the SS may be issued continuing rights to transmit, or the right
to transmit may be granted by the BS after receipt of a request
from an SS. In addition to individually-addressed messages, messages
may also be sent on multicast connections (control messages and
video distribution are examples of multicast applications) as well
as broadcast to all stations. Within each sector, users adhere to
a transmission protocol that controls contention between users and
enables the service to be tailored to the delay and bandwidth requirements
of each user application.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this
invention will become more readily appreciated as the same becomes
better understood by reference to the following detailed description,
when taken in conjunction with the accompanying drawings, wherein
like reference numerals refer to like parts throughout the various
views unless otherwise specified:
FIG. 1 is a schematic diagram of an exemplary broadband wireless
network with point-to-multipoint topology based on the IEEE 802.16
suite of standards;
FIG. 2 is a schematic diagram of a network management reference
model for broadband wireless network architecture with mobile subscriber
stations (MSSs), according to one embodiment of the invention;
FIG. 3a is a schematic diagram of a protocol layering reference
model with network management for MSSs in a broadband wireless access
(BWA) network with corresponding control, data, and management plane
software architecture, according to one embodiment of the invention;
FIG. 3b is a schematic diagram of the protocol layering reference
model with network management of FIG. 3a, further illustrating message
flows in connection with retrieving parameters from an MSS;
FIG. 3c is a schematic diagram of the protocol layering reference
model with network management of FIG. 3a, further illustrating message
flows in connection with sending parameters to an MSS;
FIG. 4a-e are schematic representations of a Management Information
(data)Base (MIB) structure employed in the network management reference
model of FIG. 2 to facilitate network provisioning and management
operations;
FIG. 5 is a flowchart illustrating operations performed to retrieve
parameters from in MSS, according to one embodiment of the invention;
FIG. 6a is a table showing the format of a TLV request message;
FIG. 6b is a table showing the format of a TLV response message;
FIG. 7 is a flowchart illustrating operations performed to provision
dynamic service flow parameters at an MSS using a proxy Simple Network
Management Protocol (SNMP) agent at a base station;
FIG. 8 is a flowchart illustrating operations performed during
provisioning service flows for a mobile subscriber station, according
to one embodiment of the invention;
FIG. 9 is a flowchart illustrating details of the service flow
provisioning operations of block 804 in FIG. 8;
FIG. 10 is a flowchart illustrating details of the dynamic service
flow parameter download operation of block 806 in FIG. 8;
FIG. 11 is a flowchart illustrating operations and logic performed
during one embodiment of a hand-over procedure used to migrate the
air interface for an MSS from a serving BS to a target BS;
FIG. 12 is a flowchart illustrating details of the hand-over procedure
operations of block 1108 in FIG. 11; and
FIG. 13 is a flowchart illustrating details of the dynamic service
flow parameter download operation of block 1112 in FIG. 11.
DETAILED DESCRIPTION
Embodiments of a method and systems of software architectures to
support network management and service provisioning for mobile broadband
wireless networks are described herein. In the following description,
numerous specific details are set forth to provide a thorough understanding
of embodiments of the invention. One skilled in the relevant art
will recognize, however, that the invention can be practiced without
one or more of the specific details, or with other methods, components,
materials, etc. In other instances, well-known structures, materials,
or operations are not shown or described in detail to avoid obscuring
aspects of the invention.
Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure,
or characteristic described in connection with the embodiment is
included in at least one embodiment of the present invention. Thus,
the appearances of the phrases "in one embodiment" or
"in an embodiment" in various places throughout this specification
are not necessarily all referring to the same embodiment. Furthermore,
the particular features, structures, or characteristics may be combined
in any suitable manner in one or more embodiments.
One of the more important aspects designed into 802.16-based broadband
wireless networks is the ability to support mobile subscribers.
Notably, this is one of the weak links with present cellular-based
networks. While modern "21/2 G" and "3 G" cellular
services enable subscribers to receive and send data from mobile
platforms, the transmission rates are relatively poor. A significant
reason for this is that the underlying delivery mechanisms (the
cellular networks) were originally intended for voice communication,
which requires relatively low transmission rates.
The MBWA architecture being standardized by the WiMAX forum Network
Working Group (NWG) is targeted to provide support for optimum transmission
rates for mobile subscribers. At the same time, the MBWA architecture
has also been designed to support the rich service capabilities
such as high-speed data, streaming videos, and voice-over-IP (VoIP)
services that were originally targeted for fixed subscriber stations
to fulfill the "last mile/first mile" service requirements.
Another important aspect of WiMAX networks is service provisioning.
To enable end-user access to a WiMAX network, the user's SS and
service flows (i.e., unidirectional flow of MAC service data units
on a connection with a particular quality of service (QoS)) must
be provisioned. Unlike the limited QoS support provided by the more
simplistic Wi-Fi (i.e., IEEE 802.11) networks commonly used to provide
wireless network access in today's environments, the IEEE 802.16
architecture supports a rich set of QoS features. Furthermore, WiMAX
employs a more sophisticated wireless air interface than does Wi-Fi,
thus requiring more complex service provisioning considerations.
More specifically, WiMAX is based on a centralized control architecture,
where the scheduler in the BS has complete control of the wireless
media access among all SS's. WiMAX can simultaneously support multiple
wireless connections that are characterized with a complete set
of QoS parameters. Moreover, WiMAX provides the packet classifier
to map these connections with various user applications and interfaces,
ranging from Ethernet, TDM (Time-Division Multiplexing), ATM (Asynchronous
Transfer Mode), IP (Internet Protocol), VLAN (Virtual Local Area
Network), etc. However, the rich feature set and flexibility in
WiMAX also increases the complexity in the service deployment and
provisioning for fixed and mobile broadband wireless access networks.
FIG. 2 shows a management reference model 200 of Broadband Wireless
Access (BWA) networks, according to one embodiment of the invention.
The model includes a Network Management System (NMS) 202, managed
base station nodes (depicted as managed nodes 204.sub.1 and 204.sub.2
for exemplary base stations 206 and 208), and a Service Flow Database
210 hosted by a database server 212. The NMS 202 and Service Flow
Database are linked in communication to the WiMAX network's BSs
(e.g., base station 206 and 208) via a network 214, which may typically
be a wide-area network (WAN) or public network (e.g., the Internet).
The BS managed nodes collect and store managed objects in an 802.16
Management Information Base (MIB) format, as depicted by MIB instances
218 and 220. In one embodiment, managed objects are made available
to NMSs (e.g., NMS 202) using the Simple Network Management Protocol
(SNMP) as specified by IETF RFC (request for comments) 1157 (i.e.,
http://www.faqs.org/rfcs/rfc1157.html).
Each of base stations 206 and 208 provide a respective coverage
area. The "footprint" (i.e., shape) of each coverage area
will generally depend on the type of antenna system provided (e.g.,
single sector, multiple sector or omni-directional) by the base
station in combination with geographical and/or infrastructure considerations
and the power of the radio signal. For example, although referred
to as non-line-of-sight (NLOS), geographical terrain such as mountains
and trees, and public infrastructure such as large buildings may
affect the wireless signal propagation, resulting in a reduced coverage
area. The radio signal strength for WiMAX transmissions are also
limited by the available RF spectrum for licensed and/or licensed-free
operations. For simplicity, the respective coverage areas 222 and
224 for base stations 206 and 208 are depicted as ovals.
A given base station is able to support communication with both
MSSs and fixed SSs within its coverage area. In order to support
complete mobility, the coverage area of proximate "neighbor"
base stations must have some degree of overlap, as depicted by an
overlap coverage area 226 in FIG. 2. As an MSS moves throughout
the coverage area (such as depicted by an MSS 228 moving between
coverage areas 222 and 224), its signal-strength data is periodically
gathered to assess which BS should be used to best maintain the
current level of service. In view of this signal strength data,
as well as other considerations detailed below, the BS used to provide
services to a given MSS will be switched as the MSS moves within
various BS coverage areas via a hand-over (HO) process. Details
of hand-over process operations are described below.
As used herein, a mobile subscriber station generally refers to
electronic device that enables communication with base stations
in a broadband wireless network. An MSS can be, for example, an
IEEE 802.16e chipset inside an express card or network interface
card, which comprises a plug-in component for a mobile client platform,
such as a notebook computer (e.g., notebook computer 230 depicted
in FIG. 2), hand-held device (PDA, pocket PC, mobile phone, etc.)
The Service Flow Database 210 contains the service flow and the
associated QoS information that directs the BS and SS/MSS in the
creation of transport connections when a service is provisioned,
an SS enters the WiMAX network, or a mobile SS roams into a BS coverage
area. In general, SSs/MSSs can be managed directly from an NMS,
or indirectly through a BS that functions as an SNMP proxy. In one
embodiment, the management information between as SS/MSS and a BS
is carried over a Primary or Secondary Management CID (Connection
Identifier) for a managed SS/MSS.
There are three types of service flows defined by the IEEE 802.16-2004
standard, including provisioned service flows, admitted service
flows, and active service flows. A provisioned service flow is a
service flow that is provisioned but not immediately activated.
External triggers are use to transition a provisioned service flow
to an admitted service flow. This service flow is initiated when
an SS enters the network through a network entry procedure, with
provision commands being managed by the NMS.
Under an admitted serve flow, a network resource is reserved through
admission control. Under one technique, external triggers are used
to transition an admitted service flow to an active service flow.
Under another technique, dynamic service addition (DSA) messages
may be employed to produce a similar result. Events similar to "off-hook"
in a telephony model are employed to activate an unsolicited grant
service (UGS) service flow. Application triggers may also be employed
to effect the transition to an active service flow.
An active service flow is a service flow that is active. That is,
it is a service flow that is granted network resources such as uplink
and downlink bandwidth for data transport usage. It employs an active
QoS parameter set that is a subset of the Admitted QoS parameter
set.
Details of one embodiment of a protocol layering reference model
with network management 300 for mobile BWA networks are shown in
FIGS. 3a, 3b, and 3c. The network management reference model includes
a network management system 302, which is used to manage various
network elements, as depicted by base stations 304 and 306 and MSSs
308 and 310. Network management system 302 includes an element manager
system (EMS) 312, which is linked in communication with a service
database 314 in which various service provider data are stored,
including data related to MSS and SS service flows (similar to that
stored in service flow database 210, traps, and events. A network
plane service access point (SAP) 316 is used to provide an interface
between EMS 312 and base stations 304 and 306 that enables the EMS
to communication with the base stations via IP transmissions, depicted
as an IP transport cloud 318.
Under a conventional EMS model, an EMS is used to manage one or
more types of network elements in the system. For example, in a
telecommunications system, an EMS may be employed to manage the
operations of various telecom switches and similar network elements.
Similar EMS 312 is used to manage network elements in the BWA system,
such as base stations 304 and 306. However, unlike the conventional
EMS model approach, the architecture of management reference model
300 enables EMS 312 to also manage mobile subscriber stations via
proxy management services provided at the base stations.
In further detail, an SNMP proxy agent is provided at each base
station, as depicted by Proxy SNMP agents 320 and 322. The proxy
SNMP agents are enabled to communicate with EMS 312 via an SNMP
manager 324 using conventional SNMP messages. SNMP is based on the
manager/agent model consisting of a manager, an agent, a database
of management information, managed objects and the network protocol.
The manager executes management applications that monitors and control
managed network elements. The agent is a management software module
that resides in a managed device to execute the commands from the
manager.
The manager and agent use a Management Information Base (MIB) and
a relatively small set of commands to exchange information via corresponding
SNMP messages. The MIB is organized in a tree structure with individual
variables, such as point status or description, being represented
as leaves on the branches. The information passed between the SNMP
manager and agents comprise one or more MIB objects encapsulated
in SNMP messages, also commonly referred to as protocol data units
or PDUs. The SNMP message format comprises a wrapper that encapsulates
a PDU along with header fields.
SNMP PDUs are arranged in classes based on their function. Table
1 below shows the SNMP PDU (Message) classes under the current version
(SNMPv3), along with the earlier SNMPv1 version PDU classes. There
are also three additional classes (Internal, Confirmed, and Unconfirmed)
which are not shown in Table 1 for simplicity.
TABLE-US-00001 TABLE 1 SNMPv3 SNMPv2/SNMPv3 PDU Class Description
SNMPv1 PDUs PDUs Read Messages that read management information
GetRequest-PDU GetRequest-PDU from a managed device using a polling
GetNextRequest- GetNextRequest-PDU mechanism PDU GetBulkRequest-PDU
Write Messages that change management SetRequest-PDU SetRequest-PDU
information from a managed device to affect the device's operation
Response Messages sent in response to a previous GetResponse-PDU
Response-PDU request Notification Messages used by a device to send
an Trap-PDU Trapv2-PDU interrupt-like notification to an SNMP InformRequest-PDU
manager
As discussed above, SNMP employs MIBs at the managed devices. This
requires 15 an SNMP agent to manage the objects in the MIB instance
for a given device. Accordingly, each of proxy SNMP agents 320 and
322 are configured to operate as a SNMP agent, in addition to performing
SNMP proxy operations described below.
Under network management reference model 300, SNMP messaging is
not employed for sending management information between a base station
and the subscribers it servers (e.g., MSSs 308 and 310). Rather,
a simplified protocol that employs Management MAC messages is used
to transfer this information.
Each of mobile subscriber stations 308 and 310 implement control
and data plane components defined by the IEEE Std. 802.16-2001 protocol
layering reference model. Under this protocol layering reference
model, the MAC layer comprises three sublayers. The MAC Service
Specific Convergence Sublayer (CS) 330 provides any transformation
or mapping of external network data, received through the CS service
access point (SAP) 332, into MAC Service Data Units (SDUs) received
by the MAC Common Part Sublayer (MAC CPS) 334 through the MAC SAP
336. This includes classifying external network SDUs and associating
them to the proper MAC service flow and Connection Identifier. It
may also include such functions as payload header suppression. Multiple
CS specifications are provided for interfacing with various protocols.
The internal format of the CS payload is unique to the CS, and the
MAC CPS is not required to understand the format of or parse any
information from the CS payload.
The MAC CPS 334 provides the core MAC functionality of system access,
bandwidth allocation, connection establishment, and connection maintenance.
It receives data from the various CSs, through the MAC SAP 336,
classified to particular MAC connections. Quality of Service is
applied to the transmission and scheduling of data over the PHY.
The MAC also contains a separate Privacy Sublayer 338 providing
authentication, secure key exchange, and encryption. Data, PHY control,
and statistics are transferred between the MAC CPS and the PHY sublayer
340 via the PHY SAP 342.
Each of mobile subscriber stations 308 and 310 also implement management
plane components depicted in the IEEE Std. 802.16-2001 protocol
layering reference model. The management plane elements include
a MAC CS management entity 344, a MAC CPS management entity 346,
a privacy sublayer management entity 348, and a PHY sublayer management
entity 350.
Although the foregoing management plane components are included
as part of the IEEE Std. 802.16-2001 protocol layering reference
model (note that in the protocol layering reference model the privacy
sublayer is actually included as part of the MAC CPS management
entity and not shown separately as depicted herein), specifications
for implementing the management plane are not included under the
scope of the IEEE Std. 802.16-2001 or the current IEEE Std. 802.16-2004
specification. This further includes communication facilities between
the control/data plane and the network management system (which
is simply depicted as an external element under the IEEE Std. 802.16-2004
protocol layering reference model), and between the management plane
and the network management system. Under the protocol layering reference
model with network management 300, these respective communication
facilities are provided by a control plane SAP 352 and a management
plane SAP 354.
Management data, in the form of MIB objects, are transferred between
the base stations and the network management system using SNMP messages
encapsulating such data. The MIB objects themselves are embodied
as PDU variable bindings comprising a bind between on object name
and its corresponding value. The management objects for a given
base station are stored in that base station's MIB instance, as
depicted by MIB instances 356 and 358 in FIG. 3a.
FIGS. 4a-e show details of various hierarchy level for a wmanIfMib
(wireless MAN interface) MIB data structure 400, according to one
embodiment. The MIB data structure includes multiple MIB objects
nested at various levels (groups) in an object hierarchy. At the
top of the hierarchy is the wmanifMib object shown in FIG. 4a. The
next hierarchy level includes the wmanifBsObjects, the wmanIfSsobjects,
and the wmanIfCommonObjects. The wmanifBsObjects include a group
of managed objects to be implemented by a base station; details
of one embodiment of the wmanifBsObjects are shown in FIGS. 4b and
4c. The wmanIfSsobjects include a group of managed objects pertaining
to subscriber station operations; details of one embodiment of the
wmanIfSsobjects are shown in FIGS. 4e. The wmanIfCommonObjects include
a group of common managed objects pertaining to both base stations
and the subscriber stations; details of one embodiment of the wmanIfCommonObjects
are shown in FIGS. 4d. In connection with other SNMP management
operations, wmanIfMib MIB data structure 400 may be implemented
as a sub-tree under the Interfaces Group MIB defined in RFC (request
for comment) 2863 (i.e., http://www.faqs.org/rfcs/rfc2863.html).
Under the conventional usage defined by the IEEE P802.16f/D2, December
2004 MIB draft specification, the wmanIfSsobjects are to be implemented
by a subscriber station. Similarly, under this MIB specification,
the wmanIfCommonObjects are to be implemented in base stations and
the subscriber stations. However, under network management reference
model 300, there are no MIB instances maintained by the MSSs. Rather,
the wmanIfSsobjects and the SS portion of the wmanIfCommonObjects
pertaining to a given MSS are stored in the MIB instance for the
base station providing service to that MSS.
Details of operations performed in connection with retrieving operation
and/or dynamic service flow parameters from an MSS under one embodiment
are shown in FIG. 5, while the corresponding message flow sequence
is depicted in FIG. 3b. The process begins in a block 500, wherein
EMS 312 generates a SNMP GetRequest message containing the MIB object(s)
corresponding to MSS parameters the EMS wants to receive from a
selected MSS. In general, the MSS will be currently served by one
of the base stations managed by network management system 302, and
will be identified by a unique identifier, such as its MAC address.
Based on active service flow information maintained in service database
314 and/or MIB 356, the base station serving the MSS can be readily
identified. For purpose of illustration, it is presumed that the
MSS is MSS 308 and the serving base station is base station 304.
After the SNMP GetRequest message is generated, it is sent from
SNMP manager 324 to proxy SNMP agent 320 at base station 304 via
network plane SAP and IP transport 318, as depicted in a block 502.
This is schematically depicted in FIG. 3b as a GetRequest message
360. In response to receiving GetRequest message 360, proxy SNMP
agent 320 extracts the MIB objects (e.g., name-value bindings) from
the message and generates appropriate management and/or control
MAC messages to retrieve the corresponding MSS parameters in a block
504. The type and number of the messages will depend on whether
the parameters are employed by the MSS's management plane or control
and data plane, and how many parameters are requested.
As depicted by a decision block 506, for each management MAC message
that is generated the logic proceeds to a block 508, wherein proxy
SNMP agent 320 sends the management MAC message 362 to management
plane SAP 354 via the primary management CID. Upon receiving a management
MAC message 362, management plane SAP 354 retrieves the requested
parameters from one or more appropriate management entities and
returns the retrieved parameters in a management MAC message 364
to proxy SNMP agent 320 via the primary management CID.
The message exchange for control MAC messages is similar, except
the MAC messages are now sent to and returned from control plane
SAP 352. In further detail, for each control MAC message generated
in block 504, decision block 506 directs the process to a block
512, wherein proxy SNMP agent 320 sends a control MAC message 366
to control plane SAP 352 via the primary management CID. Upon receiving
a control MAC message 366, control plane SAP 352 retrieves the requested
parameters from one or more appropriate control and data plane components
and returns the retrieved parameters in a control MAC message 368
to proxy SNMP agent 320 via the primary management CID.
Upon receiving the requested parameters for GetRequest 360 via
corresponding management MAC messages 364 and/or control MAC messages
368, proxy SNMP agent 320 generates an SNMP Response message in
a block 516 containing the MIB object(s) corresponding to the parameters
returned in blocks 510 and/or 514 by the MAC messages. The SNMP
Response message 370 is then sent from proxy SNMP agent to SNMP
manager 324 via IP transport 318 and network plane SAP 316 in a
block 518 to complete the MSS parameter retrieval process.
Details of embodiment of message formats used for management MAC
messages and control MAC messages are shown in FIGS. 6a and 6b.
More particularly, FIG. 6a depicts the format of a TLV (Tag/Length/Value)
Request (TLV_REQ) message that may be used for submitting a request
to management plane 354 or control plane 352 for an MSS, while FIG.
6b depicts the format of a TLV Response (TLV_RSP) message that may
be used for returning a management or control MAC response message
from management plane 354 or control plane 352 to the proxy SNMP
agent at the base station. In one embodiment management MAC messages
handled by management plane SAP 354 may be employed to convey the
following, but not limited to, parameters: Configuration file encodings
(Section 11.2 in IEEE 802.16-2004); Global parameters (Section 10.1
in IEEE 802.16-2004); PKM parameters (Section 10.2) in IEEE 802.16-2004);
MSS trap control; MSS threshold configuration; MSS performance data
(e.g., FEC counters) and MSS events.
Details of operations performed in connection with sending MIB
objects to provision dynamic service flows to BSs, and subsequent
passing of dynamic service flow parameters to an MSS under one embodiment
are shown in FIG. 7, while the corresponding message flow sequence
is depicted in FIG. 3c. The process starts in a block 700, wherein
EMS 312 retrieves data from service database 314 corresponding to
the MIB object(s) to be sent. EMS 312 then generates an SNMP SetRequest
message 372 containing the MIB objects in a block 702. In a block
704, SetRequest message 372 is sent from SNMP manager 324 to proxy
SNMP agent 320 via network plane SAP 316 and IP transport 318 as
depicted in FIG. 3c. Upon receipt of SetRequest message 372, proxy
SNMP agent 320 extracts the MIB object(s) and populates appropriate
MIB subtrees in MIB instance 356 corresponding to applicable BS
and (M)SS MIB objects, as depicted in a block 706.
In a decision block 708, a determination is made to whether any
parameters need to be sent to MSS 308. If the answer is NO, the
process is complete. If the answer is YES, the process proceeds
to a decision block 710 in which a determination is made to whether
the parameters are to be sent via a management MAC message or a
control MAC message. For each applicable management MAC message,
proxy SNMP agent 320 generates and sends a management MAC message
374 containing management plane parameters to management plane SAP
354 via the primary management CID in a block 712. The management
plane SAP then provides the sent parameter(s) to one or more targeted
management entities (as applicable) in the management plane, as
depicted by in a block 714, completing the process. For each applicable
control MAC message, proxy SNMP agent 320 generates and sends a
control MAC message 376 containing data/control plane parameters
to control plane SAP 352 via the primary management CID in a block
716. The control plane SAP then provides the sent parameter(s) to
a targeted MAC component in the control/data plane, as depicted
in a block 718, completing the process.
FIG. 8 shows a flowchart illustrating operations performed to provision
dynamic service flows for a mobile subscriber, according to one
embodiment of the invention. The process begins in a block 800,
wherein the subscriber purchases a broadband wireless service from
a service provider by specifying dynamic service flow attributes
in a service level agreement. When a customer subscribes to the
service, he or she will communicate the service provider the dynamic
service flow information corresponding to the desired level of service,
including the number of UL/DL connections that are requested, along
with the data rates and QoS parameters for those connections, and
along with what kind of applications (e.g., Internet, voice, video,
etc.) he or she intends to run. In response to the subscriber entries,
the service provider will pre-provision the services by entering
the corresponding dynamic service flow attributes in service database
314, as shown in a block 802.
In response to an MSS entering a BS coverage area, the BS downloads
dynamic service flow parameters that are provisioned for the MSS
from service database 314 in a block 804. Details of one embodiment
of these operations are shown in FIG. 9.
The process begins in a block 900, wherein an MSS performs a scanning
operation and synchronizes with BS. Generally, scanning is performed
to identify base stations within the range of the MSS and select
the best BS to provide service for the MSS. During scanning, an
MSS scans neighboring BS to measure radio signal reception strength.
In further detail, a carrier-to-interference plus noise ratio (CINR)
and/or relative-signal strength indicator (RSSI) are measured to
a resolution of 0.5 decibels (dB) using a pre-defined process and
message exchange sequence. Prior to performing a scan, an MSS and
its serving BS exchange MOB_SCN_REQ (mobile scan request) and MO_SCN_RSP
(mobile scan response) message to set up a timeframe for performing
the scan. Once a BS is selected to serve the MSS, the MSS and BS
perform a synchronization operation to establish uplink and downlink
communication channels.
In a block 902, the MSS obtains uplink and downlink parameters
from corresponding uplink channel descriptor (UDC) and downlink
channel descriptor (DCD) messages. The MSS then performs initial
ranging using RNG messages. Under this operation, the MSS sends
a RNG_REQ ranging request message to a BS, which returns an RNG_RSP
ranging response message containing current ranging information.
After successful ranging, the BS obtains the MSS's MAC (Media Access
Channel) address.
In a block 905, the BS proxy SNMP agent generates an SNMP trap
to EMS 312 via SNMP manager 324. Under the SNMP model, SNMP traps
are used to send information from an SNMP agent to an SNMP manager
(without the manager asking for the information). The SNMP trap
identifies the type of trap, and includes a variable binding identifying
the MAC address of the MSS
In a block 906, EMS 312 uses the MSS's MAC address as a lookup
parameter to download the service flow information corresponding
to the MSS (entered above in block 802) from service database 314
using SetRequest messages to pre-provision service for the MSS at
the BS. In conjunction with the operations of block 906, the wmanIfBsProvisionedSfTable
is populated with the corresponding service flow information, while
corresponding QoS parameters are entered in the wmanIfBsServiceClassTable
and corresponding classifier rules are entered in the wmanBsClassifierRuleTable.
After the appropriate BS MIB objects (e.g., tables) are populated
with the pre-provisioned service flow data, the MSS and BS exchange
subscriber basic capability (SBC) messages to negotiate basic capabilities
that both the BS and MSS agree to operate, as depicted in a block
908. Next, in a block 910, the MSS and BS use public key management
(PKM) messages for MSS authentication and authorization according
to IEEE 802.16e/D5a draft specification (December, 2004). As depicted
in a block 912, the MSS then sends a REG-REQ message to register
the MSS into the BS and receives a REG-RSP message from the BS in
reply. The BS then enters the MSS into its wmanifBsRegisteredSsTable
using its MAC address to identify the MSS. Based on the MAC address,
the BS will be able to find the service flow information that has
been pre-provisioned for the MSS in the wmanIfBsProvisionedSfTable,
the wmanIfBsServiceClassTable, and the wmanBsClassifierRuleTable.
This completes the flowchart operations of FIG. 9, with the process
returned to block 804 of FIG. 8, as depicted by a return block 914.
Continuing at a block 806 in FIG. 8, after the operations of the
flowchart of FIG. 9 are performed, the BS downloads the operational
parameters and dynamic service flow parameters as defined in the
wmanIfMib to the MSS. Details of one embodiment of the operations
for block 806 are shown in FIG. 10.
The process starts in a block 1000, wherein the proxy SNMP agent
extracts the operational parameters and dynamic service flow parameters
for the MSS from the MIB instance. Optionally, these parameters
may be extracted from the SNMP SetRequest message(s) as they are
received. In a block 1002, the proxy SNMP agent generates TLV-based
messages containing the operational parameters and dynamic service
flow parameters and sends the messages to the MSS to be received
by the management plane SAP and/or the control plane SAP, as appropriate.
The management plane SAP and/or the control plane SAP then update
appropriate operational and service flow parameters for the MSS
in a return block 1004, which returns the process to block 808 in
FIG. 8.
Continuing at a block 808, upon completing the download of the
operational parameters and dynamic service flow parameters to the
MSS, the BS uses Dynamic Service Addition (DSA) messaging to the
MSS to create dynamic service flows with the pre-provisioned dynamic
service flow information obtained in block 804 and creates corresponding
entries in the wmanIfCmnCpsServiceFlowTable. Details of the DSA
message syntax can be found in Section 6.3.2.3.10 for the DSA-REQ
message, Section 6.3.2.3.11 for the DSA-RSP message, and in Section
6.3.2.3.12 for the DSA-ACK message in IEEE 802.16-2004 standard.
The wmanIfCmnCpsServiceFlowTable contains both service flow information
and QoS parameters. Depending on the network condition, the QoS
parameters in wmanIfCmnCpsServiceFlowTable may correspond to a lower
service level than what have been pre-provisioned for a given MSS
in wmanIfBsProvisionedSfTable. In one embodiment, the classifier
rules will be created in the classifier rules table (not shown)
in the BS. The dynamic service flows will then be available for
the subscriber to send data traffic, as depicted by an end block
810. In response to appropriate conditions that invoke corresponding
triggers, the pre-provisioned service flows will be advanced to
admitted and then active service flows.
As an MSS moves throughout a network coverage area, its signal-strength
will weaken such that a hand-over (HO) process is warranted. More
particularly, the HO process is the process under which an MSS migrates
its air-interface from a (currently) serving BS to a target (for
future service) BS. Upon HO completion, the target BS becomes the
new serving BS. Under a conventional HO process, the MSS needs to
synchronize with the target BS downlink channel, obtain the uplink
parameters and perform its network re-entry process, including re-authorization,
re-registration, and re-establish its IP connectivity in a manner
similar to that employed for new MSS entering the network according
to the IEEE 802.16e/D5a draft specification (December, 2004). This
conventional HO process requires a large amount of message traffic,
resulting in a significant time-delay as well as significant workload
levels at the BSs.
Operations and logic corresponding to one embodiment of a hand-over
process are shown in FIG. 11. A hand-over begins with a decision
for an MSS to hand-over its air interface, service flow, and network
attachment from a serving BS to a target BS. Accordingly, the HO
process begins in a block 1100, wherein a determination is made
to a need or benefit to migrating an existing service from a serving
BS to a new (target) BS. The decision may originate either at the
MSS, the serving BS, or the network manager. Typically, the HO decision
will be made based on service criteria (e.g., which BS will provide
the best air-interface to the MSS) and BS bandwidth availability
considerations. In connection with this determination is the ongoing
process of cell selection.
Cell selection refers to the process of an MSS scanning and/or
ranging one or more BSs in order to determine suitability, along
with other performance considerations, for network connection or
hand-over. The MSS may incorporate information acquired from a MOB_NBR-ADV
(mobile neighbor advertisement) message to give insight into the
available neighboring BSs for cell selection consideration. If currently
connected to a serving BS, an MSS shall schedule periodic scanning
intervals or sleep-intervals to conduct cell selection for the purpose
of evaluating MSS interest in hand-over to potential target BSs.
This procedure does not involve termination of existing connections
to a serving BS and their re-opening in a target BS. If ranging
a target BS for hand-over, any newly assigned basic and primary
CIDs (connection identifiers) are specific to the target BS and
do not replace or supplant the basic and primary CIDs the MSS employs
in its communication with its serving BS.
In view of these cell selection operations, an MSS periodically
scans neighboring BS to measure radio signal reception strength.
As discussed above, a CINR and/or RSSI value is measured using a
pre-defined process and message exchange sequence, which is proceeded
by the aforementioned MOB_SCN_REQ and MOB_SCN_RSP message exchange
to set up a timeframe for performing the scan. As another option,
a serving BS may initiate scanning activities by sending a NBR_ADV
(Neighbor Advertisement) message to the MSS. The message informs
the MSS of a number of local neighbors from which it might obtain
better service. In response to the message, the MSS and serving
BS exchange MOB_SCN_REQ and MOB_SCN_RSP messages and then the MSS
scans the neighbor BSs identified in the MOB-NBR-ADV message. In
one embodiment, the determination of block 1100 is made by an MSS
in view of the foregoing scanning operations.
In connection with the foregoing hand-over determination, the MSS
sends the serving BS an MOB_MSSHO_REQ (mobile MSS hand-over request)
message to request a hand-over or the serving BS initiates a hand-over
in a block 1102. In response, the proxy SNMP agent at the serving
BS generates a trap to EMS 312 (via the SNMP manager 324) to trigger
download of service flow and QoS parameters to the target BS in
a block 1104. Upon being triggered, EMS 312 uses the MSS's MAC address
as a lookup parameter to download the service flow information corresponding
to the MSS (entered above in block 802) from service database 314
using SetRequest messages to pre-provision service for the MSS at
the target BS. In conjunction with the operations of block 1106,
the wmanIfBsProvisionedSfTable is populated with the corresponding
service flow information, while corresponding QoS parameters are
entered in the wmanIfBsServiceClassTable and corresponding classifier
rules are entered in the wmanBsClassifierRuleTable.
At this point, the MSS is ready to perform the hand-over of its
air interface from the serving BS to the target BS, the operations
of which are generally depicted by a block 1108, while details of
one embodiment of this process are shown in FIG. 12. In general,
many of the operations are similar to those discussed above with
reference to the operations of FIG. 9.
The process begins in a block 1200, wherein the MSS scans and synchronizes
with the target BS in a manner similar to that described above for
block 900 of FIG. 9. In a block 1202, the MSS then obtains the uplink
and downlink parameters via respective UCD and DCD messages in manner
similar to that described above for block 902. The MSS then performs
initial ranging using RNG messages, and the target BS obtains the
MSS's MAC address in a block 1204 in a manner similar to the operation
of block 904 described above. The MSS and BS then use SBC messages
to negotiate basic capabilities and agree on operating parameters
in a block 1206 and us PKM messages for MSS authentication and authorization
in block 1208 in a manner similar to that described above for respective
blocks 906 and 908.
In a block 1210, the target BS locates the pre-provisioned service
flow information that was downloaded from service database 314 above
in block 1106. The MSS then sends a REG message to register the
MSS into the target BS in a block 1212, and the BS enters the MSS
into it's wmanIfBsRegisteredSsTable. The processing of FIG. 12 is
then completed in a return block 1214, wherein the logic returns
to block 1108.
Upon return, the logic proceeds to a decision block 1110, wherein
a determination is made to whether the MSS is already using the
same dynamic service flow parameters as those being provisioned
by the target BS--in other words, the dynamic service flow parameters
for the serving and target BS are the same. In one embodiment, this
is identified by using a configuration tag. Under this approach,
each configuration file has an associated tag indicating the version
of the set of operational parameters and dynamic service flow parameters.
In one embodiment, a standard set of configuration files is defined
that can be reused across multiple base stations to simply the hand-over
procedure. If the answer to decision block 1110 is YES, the logic
proceeds directly to a block 1114, skipping a block 1112.
If the answer to decision block 1110 is NO, there is a need to
obtain new operational and/or dynamic service flow parameters or
the changes from the currently used parameters. Accordingly, the
target BS downloads such dynamic service flow parameters in a block
1112. Details of this process are shown in FIG. 13, and are similar
to those presented in FIG. 10 to provide dynamic service flow parameters
to an MSS entering a broadband wireless network.
The process starts in a block 1300, wherein the proxy SNMP agent
extracts the operational parameters and dynamic service flow parameters
for the MSS from the MIB instance at the target BS. Optionally,
these parameters may be extracted from the SNMP SetRequest message(s)
as they are received. In a block 1302, the proxy SNMP agent generates
TLV-based messages containing the operational parameters and dynamic
service flow parameters and sends the messages to the MSS to be
received by the management plane SAP and/or the control plane SAP,
as appropriate. The management plane SAP and/or the control plane
SAP then update appropriate operational and service flow parameters
for the MSS in a return block 1304, which returns the process to
block 1112 in FIG. 11.
Continuing at block 1114, the target BS uses DSA messages to create
service flows based on service flow information obtained in block
1106 (if the parameters are the same) or 1112 (if the parameters
are different) and creates corresponding entries in its smanIfCmnCpsServiceFlowTable.
As depicted by an end block 1116, this completes the hand-over process,
and thus the service flows for the MSS are now provided by the target
BS.
In general, the various operations performed by EMS 312 including
SNMP manager 324, proxy SNMP agent 320, management plane SAP 354
and control plane SAP 352 by corresponding software modules and/or
applications running on an appropriate host machine. Thus, embodiments
of this invention may be used as or to support software executed
upon some form of processing core or otherwise implemented or realized
upon or within a machine-readable medium. A machine-readable medium
includes any mechanism for storing or transmitting information in
a form readable by a machine (e.g., a computer). For example, a
machine-readable medium can include such as a read only memory (ROM);
a random access memory (RAM); a magnetic disk storage media; an
optical storage media; and a flash memory device, etc.
The above description of illustrated embodiments of the invention,
including what is described in the Abstract, is not intended to
be exhaustive or to limit the invention to the precise forms disclosed.
While specific embodiments of, and examples for, the invention are
described herein for illustrative purposes, various equivalent modifications
are possible within the scope of the invention, as those skilled
in the relevant art will recognize.
These modifications can be made to the invention in light of the
above detailed description. The terms used in the following claims
should not be construed to limit the invention to the specific embodiments
disclosed in the specification and the drawings. Rather, the scope
of the invention is to be determined entirely by the following claims,
which are to be construed in accordance with established doctrines
of claim interpretation.
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