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Mobile Communication

Mobile Communication. Extented-EMS. Mobile Communication. After compression, a composed bytestream is composed of two types of elements: data blocks and block references. A data block contains an uncompressed block of octets.

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Mobile Communication

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  1. Mobile Communication Extented-EMS

  2. Mobile Communication After compression, a composed bytestream is composed of two types of elements: data blocks and block references. A data blockcontains an uncompressed block of octets. On the other hand a block reference is used to identify a sequence of octets in the uncompressed stream in order to repeat the identified sequence simply by referring to it.

  3. VCard Mobile Communication This is used for representing Electronic business Cards. This format is already widely used with PDA’s and is becoming the de-facto format for the exchange of electronic business cards over infrared links. It is also becoming common to attach a vCard data stream as a signature to an email message.

  4. VCard Mobile Communication • VCard property description include. • Format <FN> • Includes prefixes titles etc. • Name <N> • Given name. • Photo • Photograph as picture, could be • GIF, BMP, JPEG. • Bday • The birthday of the person

  5. VCard Mobile Communication • VCard property description include. • Add • Address maybe, Postal, international home, work, domestic. • Tel • Preferred number • Work Number • Home • FAX • MSG • Etc.

  6. Polyphonic MIDI. Mobile Communication Melodies in the MIDI format are represented by a sequence of instructions that a “sound synthesizer” can interpret and execute. In an EMS enabled device, this MIDI sound synthesizer may be implemented either as a software-based synthesizer or as a hardware MIDI chipset. For instance an MIDI message can instruct the synthesizer to use a specific instrument or to play a given note.

  7. Polyphonic MIDI. Mobile Communication Any MIDI message is composed of an initial status octet <status byte representing type of MIDI> along with one or two data octets. This structure of an MIDI message is shown in the diagram The Synthesizer allows a number of instruments to be played simultaneously in-order to play the melody.

  8. Polyphonic MIDI. Mobile Communication Transport of MIDI melodies. In theory, MIDI messages can be sent in real-time to the synthesizer. With EMS the MIDI melody is first conveyed as part of a message and later rendered by the sound synthesizer when requested by the subscriber……

  9. Polyphonic MIDI. Mobile Communication Transport of MIDI melodies. …. For this purpose additional timing information needs to be associated with MIDI messages in order to tell the synthesizer when to play the melody notes. To achieve this, timing information along with MIDI messages are formatted as standard MIDI files <SMF> Three Formats: • SMF Format O: all MIDI messages are stored in one single track. • SMF Format 1: MIDI messages are stored as a collection of tracks. • MSF Format 2: this format is seldom supported by sound synthesizers.

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