Media Processing Node for Providing Value-added Media Services
Media Processing
Value-added Media
Media Services
Media Processing Node
for Providing Value-added Media Services
We have developed media processing node specialized for
media services that can incorporate the excellent commercially available technology to allow rapid deployment of various kinds of media communication services and efficiently
provide added value for audio, video or other media for
users.
1. Introduction
Masaru Takahashi
Hiroshi Matsunaga
tions for providing added value to
time and higher cost in order to deploy
users.
multiple services.
MPN integrates existing services
On the other hand, with MPN
kinds of services which use video,
that handle audio, video and text as
development time is shortened by hav-
audio, text or other media, construction
media data (Table 1) for provision to
ing the respective service controllers
of the ALL-IP network and introduc-
the user and also serves as a platform
share service components (enablers )
system that is capable of producing new
that are required in the execution of ser-
will allow implementation of multime-
media services. In order to develop this
vices (Fig. 1 (b)) rather than deploying
dia communication services that take
platform system, we followed a new
a combination of service controllers for
advantage of the high-speed network.
design policy.
each service and service components.
*1
*2
There is a demand for rapid deployment
Previously, media processing sys-
In addition, MPN is constructed accord-
of new media communication services
tem was mostly designed from two sep-
ing to a design policy that allows incor-
and provision of new network added
arate components. Service controllers
value to users.
for every service to control how the
For the provision of new media
each service should be executed and
communication services, an extensible
service components that implement
service provision system with a config-
media processing specialized for each
uration that allows easy addition of
service (Figure 1 (a)). This design pol-
functions is desired. To meet such
icy is effective from the viewpoint of
needs, we designed a Media Processing
system optimization that is specialized
Node (MPN) that is specialized for
for individual services, but it has the
media services and equipped with func-
disadvantage of longer development
† Currently Product Department
†† Currently R&D Strategy Department
*1 LTE: An evolutional standard of the ThirdGeneration mobile communication system
specified at 3GPP; LTE is synonymous with
Super3G proposed by NTT DOCOMO.
†0
Takuji Sakaguchi
In the context of providing different
tion of Long Term Evolution (LTE)
4
Atsuto Miyata
Core Network Development Department
Table 1 Services running on MPN
Media
Service name
Melody Call
Audio
Voice mail services
Mobiler’s check
Satellite public subscribed terminals
Video
Text
Voice mail with videophone
Video guidance service
SMS
Short mail
*2 Enabler: A function or a component of a service configuration that can be used by multiple
service scenario controllers.
NTT DOCOMO Technical Journal Vol. 11 No. 1
††
†0
†0
Service C
controller
Service
A
dedicated
component
Service
B
dedicated
component
Service
C
dedicated
component
Application group
Service B
controller
…
…
Concept for enabler
based development
Enabler group
Service A
controller
Service A
controller
Service B
controller
Services
Common component 1
(standard specifications)
(a) Previous system development
design policy
Service C
controller
Example: voice
Storing and playing
voice data
Service D
controller
Service E
controller
Services
Common component 2
(proprietary NTT DOCOMO)
Services
Common component 3
(standard specifications)
Example: voice
synthesis
…
…
Example: speech
recognition,
modeling
Common utilization
(b) System development design
policy based on enablers
Figure 1 Design policy for MPN
poration of the excellent technology
that is on the market.
expansion, the Session Initiation Proto*3
col (SIP) and Real-time Transport
*4
mercially available products, Request
For Proposal (RFP) was used.
In this article, we describe the con-
Protocol (RTP) that are used in the
MPN features this hierarchical sys-
figuration of MPN constructed for the
ALL-IP network are adopted as MPN’s
tem architecture and functional expan-
provision of value-added media ser-
internal protocols.
sibility for the service control equip-
vices and development based on a new
design policy.
2. Network Migration
When first introduced, MPN is con-
Currently, provisional conversion
ment and the media processing equip-
processing is being used to compensate
ment. An overview of the MPN system
for the differences between a future
and features is shown in items (1) to (5)
extended interface and the existing
of Figure 3.
interfaces to maintain compatibility.
3.1 Features of the System
nected to the 3G circuit-switching network to migrate the various services
3. System Overview
Architecture
which run on existing media processing
MPN has a hierarchical structure of
To simplify the introduction of
system (Table 1). In order to minimize
service control equipment and media
commercially available products for the
the modification to adjacent network
processing equipment to facilitate intro-
media processing equipment, a standard
nodes, MPN supports the interface of
duction of commercially available
protocol between the service control
existing media processing system (Fig-
products. For the service control equip-
equipment and media processing equip-
ure 2).
ment, the Advanced Telecom Comput-
ment is adopted and the operation and
*5
Nevertheless, the existing interface
ing Architecture (ATCA) platform is
maintenance functions are configured
will not be able to connect to the ALL-
adopted, considering the need for relia-
in a hierarchy. The details are described
IP network, which is being planned for
bility and redundancy in service con-
below.
near future, without modification to
trol. For the media processing equip-
MPN. Therefore, considering future
ment, in order to obtain excellent com-
*3 SIP: A call control protocol defined by the
Internet Engineering Task Force (IETF) and
used for IP-phone with VoIP, etc.
*4 RTP: A protocol defined by IETF for real-time
distribution of audio, video or other such
media.
NTT DOCOMO Technical Journal Vol. 11 No. 1
*5 ATCA: Industrial standard specifications for
carrier-oriented next-generation communication equipment specified by the PCI Industrial
Computer Manufacturers Group (PICMG).
5
Media Processing Node for Providing Value-added Media Services
HLR
HLR
IP backbone
IP backbone
SGW
Signaling system No. 7
Media processing system
Media processing system
Voice mail
service provision
equipment
Melody Call
provision
equipment
Credit/card
services provision
equipment
SMS provision
equipment
MPN
Added by conversion to ALL-IP network
AS
MGCF/
MGW
PDC exchange
node
MSC
CSCF
PDC exchange
node
MSC
IP backbone
CS-GW
PDC
3G
PDC
3G
(a) Before introduction of MPN
(b) After introduction of MPN
AS : Application Server
CSCF : Call Session Control Function
CS-GW : Circuit Switching GateWay
HLR : Home Location Register
MGCF : Media Gateway Control Function
MGW : Media GateWay
MSC : Mobile Switching Center
SGW : Signaling GateWay
Figure 2 Positioning of MPN within the core network
Integrated operation
(NW-OPS)
(4) Selective startup of service
applications
MPN
Voice mail services
ISUP
ISUP⇔SIP
conversion*
Melody Call services
…
Service application
ATCA's common operation
and maintenance platform
SIP
Common services function (middleware)
Service control equipment (ATCA platform)
(1) Use of standard
protocol
(3) Sharing and reuse of
common service functions
SIP
Operation and maintenance platform
for unified management of
commercially available products
Media control
VXML
scenario
file
STM
STM⇔IP
conversion*
VXML interpreter
RTP
(2) Hierarchical operation and
maintenance platform
DB
Media processing
(5) Implementation of guidance
scenarios using VXML
Media processing equipment
ISUP : ISDN User Part
STM : Synchronous Transfer Mode
*Temporary functions in advance of ALL-IP network
Figure 3 MPN system overview
6
NTT DOCOMO Technical Journal Vol. 11 No. 1
2) Hierarchical Operation and Mainte-
1) Adoption of Standard Protocol
ATCA platform, hence it has a very
nance Platform
high compatibility with the ATCA plat-
are basically provided with an interface
For network nodes within the
form. Also, because the MPN uses the
that uses a standard protocol. Hence, in
NTT DOCOMO core network, opera-
ATCA platform for the service control
order for service control equipment to
tion and maintenance functions are
equipment, the ATCA’s common oper-
incorporate commercially available
implemented by an integrated operating
ation and maintenance platform that has
products, standard protocols must be
system called NetWork OPeration Sys-
maintenance functions to be monitored
Commercially available products
*6
supported. In the case of MPN, SIP was
tem (NW-OPS ). For communication
adopted since a great majority of com-
between the NW-OPS and monitored
On the other hand, when designing
mercially available products for the
network nodes, Simple Network Man-
systems which require multiple com-
*7
*8
by the NW-OPS could be used.
media processing used by real-time ser-
agement Protocol (SNMP ), telnet or
mercially available products to be
vices such as Melody Call and Voice
other such general protocols are used.
added, the adding of operation and
mail services use SIP for call control.
However, those protocols are used
maintenance functions each time when
Similarly, in the future, when MPN
under proprietary specifications, so
new products are introduced is very
is required to provide additional ser-
those functions must be implemented
inefficient. Therefore, a means of mini-
vices, it will be enabled by adding com-
when performing operation and mainte-
mizing the addition of functions was
mercially available products with the
nance by NW-OPS.
necessary (Figure 4 (a)).
The NW-OPS monitors multiple
In the work described here, we
network nodes which are based on the
introduced an operation and mainte-
suitable functions.
NW - OPS
NW - OPS
ATCA's common operation and
maintenance platform
ATCA's common operation and
maintenance platform
Monitoring
Service
control
equipment
Service
control
equipment
Function
Function
development development
Commercially
available
products
Function
development
Commercially
available
products
Commercially
available
products
Function
development
Monitoring
Service
control
equipment
Service
control
equipment
Service
control
equipment
Operation and maintenance platform
for unified management of
commercially available products
Monitoring
Commercially
available
products
(a) When only ATCA operation and maintenance platform is used
Commercially
available
products
Commercially
available
products
(b) When ATCA operation and maintenance platform and commercial
product operation and maintenance platform are used
Figure 4 Example of implementing operation and maintenance for commercially available products
*6 NW-OPS: A system for maintenance
and monitoring of equipment within the
NTT DOCOMO core network.
*7 SNMP: A protocol for the monitoring and
control of communication devices (router or
computer, terminals, etc.) on a TCP/IP network.
NTT DOCOMO Technical Journal Vol. 11 No. 1
*8 telnet: Virtual terminal software for operation
of a remote server from a local computer over
a TCP/IP network, or the protocol that enables
that function.
7
Media Processing Node for Providing Value-added Media Services
nance platform for unified management
multiple service applications, so an
function can share it by simply provid-
of commercially available products to
Application Programming Interface
ing different parameters. Furthermore,
*9
solve that problem for the MPN. We
(API) is defined for each function and
the function is easily implemented for
also chose to provide a unified mainte-
functions are grouped by similarity
new service applications by using this
nance interface with the NW-OPS by
(Figure 5).
API.
2) Selective Startup of Service Appli-
means of ATCA’s common operation,
For example, Melody Call services
maintenance, and monitoring platform
require a user profile retrieval function,
cations
(Fig. 4 (b)). This kind of functional
but that same function is also required
In past systems, it was necessary to
allocation creates a hierarchy between
by Voice mail services. If an API has
develop specific systems to provide
ATCA’s common operation and main-
been specified for the profile informa-
functions for each service, even when
tenance platform and the operation and
tion retrieval function (API_B_4 in the
services were similar. Because it is dif-
maintenance platform for unified man-
example presented in the figure), then
ficult to accurately estimate user
agement of commercially available
each service application that uses the
demand for a service when constructing
products. This minimizes the effect on
ATCA’s common operation and maintenance platform when incorporating
Service control equipment
Service application
commercially available products.
Melody Call
services
3.2 Features of the Service
Voice mail
services
…
Control Equipment
To enable flexible adaptation of
adding new services, we implemented
sharing and reusing of common service
API_A
API_B
User profile
management
SIP call
control
API_C
Operation and
maintenance
…
Common service functions (middleware)
functions and selective service applications.
1) Sharing and Reuse of Common Service Functions
User profile management
MPN is assumed to handle multiple
API_B_1 Access right registration
media services, and will provide multi-
API_B_2 Access right cancellation
API_B_3 Edit profile information
ple services that handle audio media
API_B_4 Retrieve profile information
such as Voice mail services and
API_B_5 Update extended profile information
Melody Call from the initial commer-
API_B_6 Retrieve extended profile information
cial launch (Table 1). In that case, func-
API_B_7 Retrieve media guidance information
API_B_8 Retrieve scenario information
tions such as retrieving user profile
API_B_n …
information can be executed by multiple services in the same way by simply
calling the functions with different
Figure 5 Example of using common service functions and API
parameters. This allows shared use by
*9 API: An interface that makes the functions provided by the OS, middleware and other such
software available to upper-level software.
8
NTT DOCOMO Technical Journal Vol. 11 No. 1
control equipment.
facilities before introducing services, it
and it is possible to choose whether the
has been necessary to introduce extra
Because the common processes and
blade servers each provide different ser-
costly equipment that is specialized for
the processes dedicated to each service
vices or all provide the same services,
NTT DOCOMO networks to provide a
are all loaded and run in memory area
etc.
margin beyond the assumed demand to
on the blade server for the services pro-
Implementing this configuration
avert inconvenience to users caused by
vided by the blade server, processing is
allows services that can accommodate
insufficient equipment.
possible for any service (Figure 6). In
the demand with a small scale of facili-
To reduce that risk in operation,
practice, services provided by each
ties to be integrated on other servers
MPN integrates multiple services that
blade are specified by local unit system
that have surplus capacity (even if they
*10
were previously provided by individual
data
that defines MPN-specific infor-
are already providing other services).
units of equipment. In order to do so,
mation (in this example, the range of
Furthermore, the facilities required for
we chose to run all of the services pro-
subscriber numbers of Melody Call
services for which the number of users
vided by the MPN, including the ser-
users accommodated by the blade serv-
is increasing can be re-allocated from
vice applications as well as the Operat-
er (Fig. 6 (a)).
facilities dedicated to services that are
ing System (OS) and middleware, on
Multiple blade servers can be incor-
individual blade servers of the service
porated within a single MPN system,
in decline, thus making efficient use of
facilities.
Local unit system data
Melody Call
090 - XXXX - aaaa∼090 -YYYY- bbbb
Voice mail
Not set
…
…
System input
Service control equipment
Service control equipment
Service application
Service application
Service control equipment
Service application
Operating
status
Melody Call
services
Voice mail
services
…
Melody Call
services
Melody Call
services
Standby
status
Voice mail
services
…
Local unit
system data
Local unit
system data
Local unit
system data
Middleware
Middleware
Middleware
OS
OS
OS
(a) Initial system startup
(b) Referencing local unit system data and starting up service application
(c) Starting up specified service application
Figure 6 Example of selective execution of Melody Call service
*10 Local unit system data: Data that specifies
node operating conditions, information on connections to other nodes, subscriber accommodation conditions, etc.
NTT DOCOMO Technical Journal Vol. 11 No. 1
9
Media Processing Node for Providing Value-added Media Services
3.3 Features of the Media Pro-
ly, to guide user actions. In convention-
processing control, profile manage-
al systems, the guidance scenario is a
ment, etc, and service-specific process-
For flexibility in service changes
program on the service control equip-
ing require real-time execution, so the
with respect to the media processing
ment and an integral part of the system.
programs are implemented with a com-
equipment, we introduced guidance
It was therefore necessary to update the
piled language. For the media process-
scenario control that employs Voice
program files when changing the guid-
ing equipment, on the other hand, there
eXtensible
ance scenario, which made speedy pro-
is a need for flexible changing and
vision of services difficult.
extension of services, so the guidance
cessing Equipment
Markup
Language
*11
(VXML ).
To avert that issue, we reconsidered
1) Implementation of Guidance Sce-
scenario is implemented with VXML,
an interpreted language.
nario Control Using VXML
the deployment of the guidance sce-
Many of the services provided by
nario control and processing functions
VXML provides Voice XML tags
an MPN, such as Voice mail services,
for the MPN and allocated the guidance
that can be used to compose a guidance
use guidance scenarios. A guidance
scenario to the media processing equip-
scenario. The operations for executing
scenario is the use of a program to send
ment side, operating on the basis of
and updating a guidance scenario are
audio messages such as “This is
control from the service control equip-
shown in Figure 7.
NTT DOCOMO.” from the system to a
ment.
Guidance scenarios described in
In service control equipment, call
user for menu transitions and, ultimate-
Service control equipment
Service control equipment
Call control /
service control
Call control /
service control
(1) Execution instruction
(1) Execution instruction
Media control
(3) Scenario
startup
VXML
interpreter
(6) Delivering
guidance message
VXML are stored as files in a DB built
(3) Scenario
startup
(2) Retrieve
Guidance
scenario
file
(VXML)
(4) Playing
instruction
Media
processing
DB
Media control
VXML
interpreter
(6) Delivering new
guidance message
(2) Retrieve
(4) Playing
instruction
Media
processing
DB
(5) Playing guidance
message
(5) Playing guidance
message
Media processing equipment
Media processing equipment
(a) When guidance scenario is executed
New
guidance
Old guidance
scenario
scenario
file
file (VXML)
(VXML)
Exchange of
new and old files
(b) When guidance scenario is updated
Figure 7 Example of guidance scenario execution and updating
*11 VXML: An XML-based language used by
automatic response systems, etc. defined by the
World Wide Web Consortium (W3C). The
structure of interactive applications can be
described with XML.
10
NTT DOCOMO Technical Journal Vol. 11 No. 1
for each service. When the media pro-
the guidance scenario file that is pulled
making the guidance scenario freely
cessing equipment receives execution
into memory is changed, so there is no
customizable for each user by using the
instructions from the service control
change in the operation of the VXML
VXML described in Section 3.3 1).
equipment, it retrieves the guidance
interpreter. This allows changes in the
scenario file, obtains the results from
on-line guidance scenario.
Examples for the incorporation of
new media processing functions include
a text to speech function for audio out-
the VXML interpreter of the media
controller, and the media processing
4. Conclusion
unit plays the guidance audio in the
order described by the scenario.
put of text data and a speech recognition function for converting spoken
We have briefly described the MPN
words to text.
constructed to provide value-added
A guidance scenario can be updated
media services and a design policy
Furthermore, specifications are cur-
by replacing its DB file. The service
aimed at active incorporation of com-
rently under discussion in Global Sys-
control equipment is unaware of the
mercially available products.
tem for Mobile communications Association (GSMA)
*12
change to a new guidance scenario, and
In future work, we will continue to
continues to execute the instructions as
investigate extension of the MPN func-
tion of a Rich Communication Suite
before. The media processing equip-
tions and incorporation of new media
(RCS)
ment also continues to access and inter-
processing functions for further devel-
media (Figure 8). As shown in Fig. 8,
pret the VXML file, unaware of any
opment of value-added media services.
while users are expected to accept rich
change in the guidance scenario. Only
An example of functional extension is
communication services, technology for
*13
toward the realiza-
that makes advanced use of
MPN
IM
（Instant Messaging）
Service provision
Content
Sharing
Presence
NTT DOCOMO network
How long until arrival?
Have a look at this...
090-xxxx-xxxx
OK
090-xxxx-yyyy
[email protected]
Very soon!
I'll be at the gate, then.
IM
Content sharing
during IM
090-yyyy-xxxx
OK
090-yyyy-yyyy
Out of
service
Sharing of presence
information
Figure 8 Future services
*12 GSMA: An international industrial organization that represents mobile phone companies.
*13 RCS: A group of services that uses Presence,
IM (*14) and Content Sharing (*15) to allow
spatial and temporal sharing as a basic communication tool with telephony and e-mail.
NTT DOCOMO Technical Journal Vol. 11 No. 1
11
Media Processing Node for Providing Value-added Media Services
*14
Instant Messaging (IM)
*15
Sharing
and Content
is the most compatible with
MPN and those functions are expected
to be relatively easy to implement
[3] H.Aoyama et. al: “Card Service Control
[1] K.Inoue et. al: “Expansion of Melody
Processor for Credit Services MCSCP,”
Call for Enhanced Music Services,”
NTT DoCoMo Technical journal, Vol. 9,
NTT DoCoMo Technical journal, Vol. 10,
No. 2, pp. 52-56, Jul. 2001 (In Japanese).
No.1, pp. 42-49, Jun. 2008.
[4] S.Okubo et. al: “Converting to the IP-
through combinations of the media pro-
[2] H.Mouri et. al: “Function Extension for
based FOMA Voice Network for
cessing functions that are already pro-
Video Mail Services for Video Phones,”
Advanced Services and Economization,”
NTT DoCoMo Technical journal, Vol. 14,
NTT DOCOMO Technical journal, Vol. 10,
No. 3, pp. 38-43, Oct. 2006 (In Japan-
No. 2, pp. 17-22, Sep. 2008.
vided and new commercially available
products.
*14 IM: A service technology that allows simple
text conversations between two persons or
among multiple persons.
*15 Content Sharing: A service technology that
allows the sending and receiving of photographs, video, etc. during communication to
12
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NTT DOCOMO Technical Journal Vol. 11 No. 1