Scalable voip mobility intedration and deployment- P6: The term voice mobility can mean a number of different things to different people. Two words that can be quite trendy by themselves, but stuck together as if forgotten at a bus station long past the last ride of the night, the phrase rings a number of different, and at times discordant, bells. | 48 Chapter 2 Table g-Law Encoding Table Input Range Number of Intervals in Range Spacing of Intervals Left Four Bits of Compressed Code Right Four Bits of Compressed Code 8158 to 4063 16 256 0x8 number of interval 4062 to 2015 16 128 0x9 number of interval 2014 to 991 16 64 0xa number of interval 990 to 479 16 32 0xb number of interval 478 t o 223 16 16 0xc number of interval 222 to 95 16 8 0xd number of interval 94 to 31 16 4 0xe number of interval 30 to 1 15 2 0xf number of interval 0 1 1 0xf 0xf -1 1 1 0x7 0xf -31 to -2 2 15 0x7 number of interval -32 to -95 4 16 0x6 number of interval -223 to -96 8 16 0x5 number of interval -479 to -224 16 16 0x4 number of interval -991 to -480 32 16 0x3 number of interval -2015 to -992 64 16 0x2 number of interval -4063 to -2016 128 16 0x1 number of interval -8159 to -4064 256 16 0x0 number of interval leading one and to record the base-2 binary exponent. This is how floating-point numbers are encoded. Let s look at the previous example. The number 360 is encoded in 16-bit binary as 0000 0001 0110 1000 with spaces placed every four digits for readability. A-law only uses the top 13 bits. Thus as this number is unsigned it can be represented in floating point as binary x 25. The first four significant digits ignoring the first 1 which must be there for us to write the number in binary scientific notation or floating point are 0110 and the exponent is 5. A-law then records the number as 0001 0110 where the first bit is the sign 0 the next three are the exponent minus four and the last four are the significant digits. A-law is used in Europe on their telephone systems. For voice over IP either will usually work and most devices speak in both no matter where they are sold. The distinctions are now mostly historical. Voice Mobility Technologies 49 compression preserves the number of samples and keeps each sample independently of the others. Therefore it is easy to figure out how the samples .
