Analysis Channel (1xEV-DO)
Pilot (See 1xEV-DO Standard Setups/Presets Table.)
specifies the forward channel that will be used for analysis and trace data results. Use the drop-down list to select one of these ForwardLink channels:
- Pilot channel
- Medium Access Control channel.
- Data channel (Forward Traffic channel or Control channel data).
- Preamble channel
- - The Pilot Channel shall consist of all-'0' symbols transmitted on the I channel with Walsh cover 0. Each slot shall be divided into two half slots, each of which contains a pilot burst.
- - Forward Medium Access Channel. The Mac channel consists of two sub-channels: the Reverse Power Control (RPC) channel and the Reverse Activity (RA 1) Random Access, or 2) Receiver Address) channel. The RA channel transmits a reverse link activity bit (RAB Radio Access Bearer) stream. The MAC (Medium Access Control: In most wired and wireless networks, a mthod is used to control how and when a device can transmit data over the communications link. This is the network's Medium Access Control scheme. The MAC protocol operates within the Data Link layer (Layer 2) of the ISO OSI 7 layer Model. The IEEE 802.11 standard, for example, specifies the MAC protocol for sharing of the wireless medium, packet formats, addressing, eror detection and recovery following errors. channel symbol is BPSK Binary phase shift keying - A type of phase modulation using 2 distinct carrier phases to signal ones and zeros. modulated on one of 64 64-ary Walsh codeword (covers). MAC symbol Walsh covers are transmitted 4 times per slot in two bursts of 64 chips each. The two burst are transmitted immediately preceding and following the pilot burst in a slot.
- - The Data channel comprises either the Forward Traffic Channel or Control Channel data. The Traffic Channel carries user data packets transmitted at variable data rates from 38 kbps to 2.4576 Mbps utilizing QPSK Quadrature phase shift keying, 8PSK or 16QAM symbol modulation. The Control Channel carries control messages, and it may also carry user traffic. Each channel is further decomposed into code-division-multiplexed quadrature Walsh channels.
- - The Preamble section is not present in every slot and may change length depending upon the data rate. The Preamble may be 64, 128, 256, 512 or 1024 chips in length and replaces an equivalent number of chips in the Data channel of a slot.
For more information, see 1xEV-DO Modulation Overview - Forward Channel TDM Structure.
See Also
