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SMS & MMS

SMS & MMS. Justin Champion C208 Ext:3723 www.staffs.ac.uk/personal/engineering_and_technology/jjc1. SMS & MMS. Contents What is SMS How it Works Infrastructure Required What is MMS Infrastructure Required. SMS & MMS. Short Messaging Service (SMS) Also known as Simple Message Service

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SMS & MMS

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  1. SMS &MMS Justin Champion C208 Ext:3723 www.staffs.ac.uk/personal/engineering_and_technology/jjc1

  2. SMS & MMS • Contents • What is SMS • How it Works • Infrastructure Required • What is MMS • Infrastructure Required

  3. SMS & MMS • Short Messaging Service (SMS) • Also known as Simple Message Service • Intention • Designed as a replacement for the Pager • The pager allows text messages to be sent to the device • To respond you must get to a phone • Still widely used, in • Hospitals • Military • Police • Industry

  4. SMS & MMS • SMS allowed • Two way communications of the text messages • Maximum character length of 160 characters • This can change though depending on the operator or the character set used • Character sets supported are • ASCII + additional European characters • Unicode • First Text • Was sent in December 1992, to a Vodafone device • Sent by Neil Papworth, saying “Merry Christmas” • Standard • Defined by ETSI and is known as “GSM 03.40”

  5. SMS & MMS • SMS Continued • The success is SMS was never planned for! • It was only ever intended as the Pager replacement, with limited use • This will explain some of the design decisions made • Usage in the UK alone • December 2003, 20.5 Billion messages sent over the four largest operators • (news.bbc.co.uk/1/hi/technology/3422475.stm, 2004) • Consider this at 8 Pence a time!

  6. SMS & MMS • GSM • At a defined time interval in GSM all devices will listen to a transmission. • This is when a Digital Control Channel (DCCH) packet of information is being sent across the network. • These DCCH packets are used to transfer essential information into the devices. • Information like a call is in coming • Paging signals from the Base stations, to work out if a handover is needed • One of these packet formats is called SMS point to point messaging, Paging, access control channel (SPACH) • This message type can be used to carry a text message. • Advantage of this method is a text message can still be delivered during a phone conversation.

  7. SMS & MMS • SMS Packet format • All data is transferred in a single DCCH SPACH packet

  8. SMS & MMS • SMS • What a packet looks like • Example SMS transmission packet saying “Hello” (www.spallared.com/nokia/smspdu/smspdu.htm#_Toc485435709, 2003)

  9. SMS & MMS • SMS delivery • Takes no additional allocation of channels • Will still work on a none packet switched infrastructure • Device does not need to continuously listen for a SMS delivery warning • Using this DCCH format, SMS will work on a large number of digital networks • GSM - Europe • PCS - American • PDC - Japan

  10. GSM SMS Infrastructure Base Station Base Station SMSC HLR SMS & MMS • SMS Infrastructure • One additional server needs adding to the GSM network • Short Message Service Centre (SMSC) HLR = Home Location Register Other Mobile Phone Network

  11. SMS & MMS • SMSC • This is a combination of hardware and software • The SMS message will be stored at this location on a FIFO basis • If the messages destination is within the local network • The HLR, is queried to find the current location of the intended device • The HLR will also inform if the device is currently turned on • If the device is off then the HLR is informed that there is a message waiting • When the device turns on the HLR informs the SMSC • The message will then be forwarded to the device • If the device is turned on, the message will be forwarded to that location

  12. SMS & MMS • SMSC • Device is outside of the network • The message will be forwarded to the SMSC of that network, where deliver will be the same as before

  13. SMS & MMS • Evolution • Operators recognised the massive potential of data services • They looked at developing SMS • Result was • Enhanced Messaging Service • Allowed additional data to be sent beyond SMS • Text formatting • Multimedia Messaging Service • Discussed in this lecture

  14. SMS & MMS • Evolution

  15. SMS & MMS • Latest Technology • Multimedia Messaging Service (MMS) • Allows the transfer of more than text between mobile devices • These devices do not need to be compatible! • In the event of a none compatible device being sent a MMS, they will receive an Internet link instead • The message can then be view on the Internet at a later stage • MMS • Is only available on GRPS devices and newer

  16. SMS & MMS • MMS • The following are the current standards • The standards can be expanded in the future • This is a list of base requirements for devices to be given the title of MMS compatible • Pictures • JPEG, GIF, PNG, SVG-Tiny (2D Vector Graphics) • Movies • MPEG-4 • Sound • SP-MIDI • Adaptive Multi Rate (AMR) • Text • ASCII Text • UTF 8/16 • Future Use • Allows unlimited expansion

  17. SMS & MMS • MMS • Additional information about how to present the Media can also be transferred • If this is not present the device will make the decision • Formats are WML, XML or SMIL • Synchronised Multimedia Integration Language (SMIL) • SMIL allows for time dependent display of information • Allowing for example a presentation to be shown on the device

  18. SMS & MMS • MMS Delivery • SMS was delivered in a single packet • MMS can have a theoretical unlimited message size • In reality the operators/devices will control the size of the messages • This indicates that the message can not be delivered in a single packet • Number of packets will depend on the type of messages sent, as with TCP

  19. SMS & MMS • MMS Transport • MMS packets will be transferred using the WAP protocol in GSM based networks • This gives security in the messages • Access to the Internet to move MMS message if needed to the Internet • The User agent at the application layer is changed to deal with MMS • Remember WAP is only a transport protocol • Your WML display is just another user agent

  20. SMS & MMS • MMS Delivery continued • MMS message will be transferred in the spare capacity • The media will be trickled to your device • You will only be informed of a message once all of the data is in the device • If you device does not have the storage to display a movie, then the data can be streamed into your device • Reducing the overhead for storage, but increasing the overhead for the network. • This will not be available until 3G (UMTS in Europe) • MMS is not platform dependent • Meaning that any mobile system can use this technology

  21. SMS & MMS • Paying for MMS ? • SMS was simple the sender paid a set amount • This is now an issue with the potential large amounts of data to be sent • As MMS can in the future be linked to the Internet how will pay for data coming from it? • This is an issue which will need resolving • Billing needs to be as simple as SMS to be effective • Users do not want to get a bill which says you have received 0.65 Mbytes of data to most people it means nothing

  22. SMS & MMS • MMS Infrastructure Internet MMS Infrastructure Base Station MMSE MMSE = MMS Environment HLR

  23. SMS & MMS • Multimedia Messaging Service Environment (MMSE) • Generic name for all of the servers which need to provide information to send a MMS • These can be in more than one network • Consider this when you are roaming • MMS Centre (MMSC) • Storing the MMS message until delivery the same as SMSC • MSS Relay • Allows delivery of information over different packet switched networks • Records usage for charging • Conversion of the messages • This will be based upon the specification of the device • Using WAP 2.0 • HLR • Allows the discovery of the status/location of a device • MMS Value Added Services (VAS) • Allowing the adding of high quality multimedia in a MMS, provided by the operator

  24. SMS & MMS • MMS Future • The initial take up of MMS has not been as good as expected • MMS sending is expected to be 1% of the market this year • (www.w2forum.com/MMS_Extract.pdf, 2004) • Reasons • Uncertainty about the technology • Expense • Lack of MMS capable devices • The usage of MMS should increase • This will reduce the cost of the messages • MMS capable equipment will become available as people naturally replace there phones • Due to adverts the understanding of the technology is increasing

  25. SMS & MMS • Link • MMS standards document • www.wmlclub.com/docs/especwap2.0/WAP-205-MMSArchOverview-20010425-a.pdf • WAP Version 2.0 • www.wapforum.org/what/WAPWhite_Paper1.pdf

  26. SMS & MMS • Conclusion • SMS • MMS

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