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Chapter 6 Interfaces and Protocols
F
IGURE
23 CDMA2000 1
X
U
M
I
NTERFACE
P
ROTOCOL
R
EFERENCE
M
ODEL
The physical layer is a bottom layer, covering various physical
channels. It provides basic radio channels to transmit infor-
mation of upper layers.
�
The data link layer comprises of Medium Access Control (
MAC
)
sublayer and Link Access Control (
LAC
) sublayer. The MAC sub-
layer implements the mapping between logical channels and
physical channels and delivers the Radio Link Protocol (
RLP
)
function. The LAC sublayer performs authentication, automatic
request retransmission, addressing, segment and reassembly.
�
The uppermost layer provides signaling service, voice service,
packet data application and circuit data application, and imple-
ments radio resource, mobility and connection management of
the air interface through signaling service.
CDMA2000 1x EV-DO Um interface
The CDMA2000 1x EV-DO Um interface is divided into application
layer, stream layer, session layer, connection layer, security layer
and physical layer. The Um interface meets the IS-856 protocol
standard. Every layer defines one or more protocols to realize its
function.
Figure 24
illustrates the overall protocol reference model.
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