Pilot Channel

FPiCH is the simplest and the most important that every carrier used continuously transmit it.
It transmits only '0's so it actually transmit PN code.

After sync, it works as a timing and phase reference. In addition, the de-modulation of recevied channels.

MAC layer

First of all, MAC layer is shared by all the users.

MAC => refers to OSI layer 2

Layers communicate using messages, act like objects.

Signaling Channels -> carry user data

Key requirement for 3G: high-data rate.

The physical layer should be more efficient to do that.
In IS-95, the signaling information is carried by traffic(fundamental) channel.

In IS-2000, separate signaling channels are the option.

F-DCCH:
可以用來傳輸零星的SMS之類的Low-rate data 而不用浪費資源開一個CHANNEL
有兩種 20ms/5ms 的FRAME

Physical Layer

實體層控制BITS(被組織成FRAME)的傳輸
錯誤偵測和校正的FUNCTION也在此層被實做
MODULATION: 把BIT, WAVEFORM互轉換也是此層工作

CHANNELIZATION: 分別不同使用者的FUNCTION
(IS-2000/95都是用ORTHOGONAL和NEAR-ORTHOGONAL法分CHANNEL)

Signaling channel: 是指賦載訊號和控制的頻道 可以分為DEDICATED和COMMON兩種types (assigned給單一使用者或是SHARED)

User channel: for user information, voice, low-rate data (SMS) , high-rate (video streaming)
三種physical channels, F-FCH, F-SCCH, F-SCH(新的)

CDMA 2000 Architecture

架構分為三層

1. Physical layer:
Bits在空氣中的傳送接收
轉換訊號 提供bit/frame level的error control

2.1. Medium access control sublayer:
控制空氣中不同的使用者
實做analogous functions as a MAC entity以控制LAN
manages the access of different (low-speed voice and high-speed data) users to the shared air interface.
2.2. Signaling link access control sublayer:
提供可靠度

3. Upper layer:
負責整體IS-2000系統控制
It exercises this control by serving as the point that processes all and
originates new signaling messages. The information (both data and voice) messages
are also passed throughhere