the V.29 specifies 4 bits per symbol, at a symbol rate of 2,400 baud, giving an effective bit rate of 9,600 bits per second. The history of spread spectrum goes in the opposite direction, leading to fewer and fewer data bits per symbol in order to spread the bandwidth. In the case of GPS, we have a data rate of 50 bit/s and a symbol rate of 1.023 Mchips/s. If each chip is considered a symbol, each symbol contains far less than one bit (50 bit/s / 1,023 ksymbols/s ≈ 0.000,05 bits/symbol). The complete collection of M possible symbols over a particular channel is called a M-ary modulation scheme. Most modulation schemes transmit some integer number of bits per symbol b, requiring the complete collection to contain M = 2b different symbols. Most popular modulation schemes can be described by showing each point on a constellation diagram, although a few modulation schemes (such as MFSK, DTMF, pulse-position modulation, spread spectrum modulation) require a different description. Significant condition In telecommunication, concerning the modulation of a carrier, a significant condition is one of the signal's parameters chosen to represent information. A significant condition could be an electric current (voltage, or power level), an optical power level, a phase value, or a particular frequency or wavelength. The duration of a significant condition is the time interval between successive significant instants. A change from one significant condition to another is called a signal transition. Information can be transmitted either during the given time interval, or encoded as the presence or absence of a change in the received signal. Significant conditions are recognized by an appropriate device called a receiver, demodulator, or decoder. The decoder translates the actual signal received into its intended logical value such as a binary digit (0 or 1), an alphabetic character, a mark, or a space. Each significant instant is determined when the appropriate device assumes a condition or state usable for performing a specific function, such as recording, processing, or gating. See also Bandwidth (computing) Bitrate Chip rate Constellation diagram, which shows (on a graph or 2D oscilloscope image) how a given signal state (a symbol) can represent three or four bits at once. Gross bit rate, also known as data signaling rate or line rate. List of device bandwidths Pulse-code modulation References External links What is the Symbol rate? What’s The Difference Between Bit Rate And Baud Rate?,