Enabling Technologies for Wireless E-Business phần 8 pps

11.3.4 Architecture

MMS is an application-level service that fits into the current WAP architecture.

The basic concept of sending an MMS message is exactly the same as that of

SMS. The originator addresses the receiver, the message is first sent to the MMS

center (MMSC) associated with that receiver, then the MMSC informs the receiver

and attempts to forward the message to the receiver. If the receiver is unreachable,

MMSC stores the message for some time, and if possible, delivers the message

ally discarded. In fact, it is a much more complicated process. To enable this

Mobile Network B

MMS Server

MMSC

Home Location

Register

MMS VAS

Applications

Post Processing

System

External

Server

Roaming MMS Wireled E-mail User Agent Client

MM5

MM8

MM7 MM6

MM3 MM4

MM2

MM1

MMS Relay

MMS User

Data Base

Internet / IP Network

2G/3G Mobile

Network A

Message

Store

MMSE

MMS User Agent

Online Charging

System

MM9

Fig. 11.6. MMS architectural elements

The whole MMS environment (MMSE) encompasses all necessary service

elements for delivery, storage, and notification. The elements can be located

within one network, or across several networks or network types. In the case of

roaming, the visited network is considered a part of that user’s MMSE. However,

subscribers to another service provider are considered to be a part of a separate

MMSE.

The MMS relay and MMS server may be a single logical element or may be

separate. These can be distributed across different domains. The combination

of the MMS relay/server is the MMSC. It is in charge of storing and handling

later. If the message cannot be delivered within a certain time frame, it is eventu￾266 Y. Yang and R. Yan

service, a set of network elements is organized as shown in Fig. 11.6 [14] .

267

among different messaging systems. It should be able to generate charging data

for MMS and VAS provider-related operations.

MMS user database contains user-related information such as subscription and

configuration.

MMS user agent is an application layer function that provides the users with the

ability to view, compose, and handle multimedia messages. It resides on the user

equipment (UE) or on an external device connected to the UE or MS.

MMS VAS applications provide VAS to MMS users. They can be seen as fixed

MMS user agents but with some additional features like multimedia message

recall between MMS VAS applications and MMSC. MMS VAS applications

should be able to generate the charging data when receiving/submitting

multimedia messages from/to MMSC.

External servers may be included within, or connected to, an MMSE, e.g.,

e-mail server, SMSC, and fax. MMSC would integrate different server types

across different networks and provide convergence functionality between external

servers and MMS user agents.

MM1 is the reference point between the MMS user agent and the MMSC. It is

used to submit multimedia messages from MMS user agent to MMSC, to let the

MMS user agent pull multimedia messages from the MMSC, let the MMSC push

information about multimedia messages to the MMS user Agent as a part of a

multimedia message notification, and to exchange delivery reports between

MMSC and MMS user agent.

MM2 is the reference point between the MMS relay and the MMS server. Most

MMS solutions offer a combined MMS relay and MMS server as a whole MMSC.

This interface has not been specified till now.

MM3 is the reference point between the MMSC and external messaging sys￾MMSC. To provide flexible implementation of integration of existing and new

framework the MMSC communicates with both MMS user agent and external

servers. It can provide convergence functionality between external servers and

MMS user agents, and thus enables the integration of different server types across

different networks.

MM4 is the reference point between the MMSC and another MMSC that is

within another MMSE. It is in charge of transferring messages between MMSCs

belonging to different MMSEs. Interworking between MMSCs will be based on

11 Mobile Content Delivery Technologies

MM5 is the reference point between the MMSC and the HLR. It may be used

to provide information to the MMSC about the subscriber to the MMSC.

incoming/outgoing messages and is responsible for the transfer of messages

tems. It is used by the MMSC to send/retrieve multimedia messages to/from ser￾vers of external messaging systems that are connected to the service provider’s

the MMS makes use of the protocol framework depicted in Fig. 11.7. In this

In MMSE, elements communicate via a set of interfaces [14].

services together with interoperability across different networks and terminals [14],

SMTP according to IETF STD 10 (RFC2821) [15] shown in Fig. 11.8.

MMS User

Agent

MM1 Transfer

Protocol

MM1 Transfer

Protocol

MM3 Transfer

Protocol

MM3 Transfer

Protocol

Lower Layer A Lower Layer A Lower Layer B Lower Layer B

e.g. TCP/UDP e.g. TCP/UDP

External

Server

MMS Capable

UE/MS MMSE

MM1 MM3

MMSC

Protocol tlements necessary in the terminal

Protocol tlements necessary in the MMSE

Additional protocol elements necessary to include external servers

Fig. 11.7. Protocol framework to provide MMS

MMS User

Agent A

MMS User

Agent B MMSC A MMSC B

SMTP

MM1 MM4 MM1

MMSE

Service Provider A

MMSE

Service Provider B

Fig. 11.8. Interworking of different MMSEs

MM6 is the reference point between the MMSC and the MMS user database.

MM7 is the reference point between the MMSC and the MMS VAS applica￾tions. It allows multimedia messages transferring from/to MMSC to/from MMS

MM8 is the reference point between MMSC and the postprocessing system. It

is needed when transfering MMS-specific CDRs from MMSC to the operators in

the postprocessing system.

MM9 is the reference point between MMSC and online charging system. It is

used to transfer charging messages from MMSC to the online charging system.

268 Y. Yang and R. Yan

VAS applications. This interface will be based on SOAP 1.1 [16] and SOAP mes￾sages with attachments [17] using an HTTP transport layer.

269

11.3.5 Transactions

There are four typical MMS transactions:

• Mobile-originated (MO) transaction is originated by an MS. The multi￾media messages are sent directly to an MS or possibly to an e-mail

address. If some sort of processing/conversion is needed, the multimedia

• Mobile-terminated (MT) transaction sends the messages to an MS. The

originator of such messages can be another MS or an application.

• Application originated (AO) transaction is originated by an application

and terminated directly an MS or another application. Before the multi￾media messages are sent to the destination, they can be processed in one

or more applications.

• Application-terminated (AT) transaction is terminated at an application

and originated by an MS or another application. As noted in MO transac￾tion, the multimedia messages can be sent to an application that does the

processing/conversion, so it is actually an AT transaction.

Based on these four types of transactions, transactions for each interface are re￾alized that can be described in terms of abstract messages. The abstract messages

can be categorized into transactions consisting of “requests” and “responses.” To

label the abstract message, the transactions for a certain interface are prefixed by

its name, e.g., the transactions for MM1 are prefixed with “MM1.” Besides,

“requests” are identified with “.REQ” as a suffix and “responses” are identified

with the “.RES” suffix.

Each abstract message carries certain IEs, which may vary according to the spe￾cific message. All messages carry a protocol version and message type, so that the

MMSE components are able to properly identify and manage the message contents.

The mapping of abstract messages to specific protocols is not necessarily a one-to￾one relationship. Depending on the MMS WAP implementation, one or more

abstract messages may be mapped to a single lower layer PDU and vice versa. The

following clause uses MM1 WAP implementation for further discussion.

11.3.6 WAP Implementation of MM1

As noted earlier, WAP addresses the protocol implementation of the particular

interface. Now, MMS activities of the WAP Forum have been integrated to OMA.

There are two different configurations of the WAP architecture and protocol

11 Mobile Content Delivery Technologies

messages are first are sent to an application that does the processing/

conversion, and then to the destination.

stacks for implementation of MMS as shown in Fig. 11.9 and Fig. 11.10.