02 utran structure
Post on 05-Apr-2018
248 Views
Preview:
TRANSCRIPT
-
7/31/2019 02 UTRAN Structure
1/44
UMTS Terrestrial
Radio Access Network
(UTRAN)
Xiong.bingjie@zte.com.cn
063361
mailto:Xiong.bingjie@zte.com.cnmailto:Xiong.bingjie@zte.com.cn -
7/31/2019 02 UTRAN Structure
2/44
UTRAN Structure & Interface
-
7/31/2019 02 UTRAN Structure
3/44
UMTS Architecture
CN
UTRAN
UE
Uu
Iu
UTRAN UMTS Terrestrial Radio Access NetworkCN Core NetworkUE User Equipment
-
7/31/2019 02 UTRAN Structure
4/44
UTRAN Architecture
RNS
RNC
Node B Node B
Iub Iub
Core Network
RNS
RNC
Node B Node B
Iub Iub
Iu Iu
Iur
UTRAN consists of many Radio Network Subsystems (RNSs) belonging to one operator.A RNS consists of one Radio Network Controller and one or more Node B(s) (base stations).The operation of RNC is similar to the GSM BSC. i.e., responsible for radio resourceallocation, execution of handover, terrestrial channel management and mapping between radioand terrestrial channels.
The only main difference between UTRAN and GSM architectures is that, in the case ofUTRAN, there is a logical connection between RNCs.
-
7/31/2019 02 UTRAN Structure
5/44
Radio Interface protocol architecture (Layer Model) -------- Iu-CS
-
7/31/2019 02 UTRAN Structure
6/44
Radio Interface protocol architecture (Layer Model) -------- Iu-PS
Iu UP Protocol
Layer
-
7/31/2019 02 UTRAN Structure
7/44
Radio Interface protocol architecture (Layer Model) -------- Iub
-
7/31/2019 02 UTRAN Structure
8/44
Radio Interface protocol architecture (Layer Model) -------- Iub
-
7/31/2019 02 UTRAN Structure
9/44
Radio Interface protocol architecture (Layer Model) -------- Uu
L2/MAC
L2/RLC
L1
MAC
RRC
PHY
TransportChannels
LogicalChannels
C-plane signaling U-plane information
GC Nt DC
GC General ControlNT NotificationDC Dedicated ControlRRC Radio Resource ControlRLC Radio Link Control
MAC Medium Access Control
RLC
BMC
PDCP
L3
PDCP Packet Data ConvergenceProtocol
BMC Broadcast and Multicast Control
-
7/31/2019 02 UTRAN Structure
10/44
Issues to Radio Interface Layers
The radio interface has two planes: C-plane signalling and U-plane information
and three layers: physical layer (L1), data link layer (L2) and network layer (L3). Service Access Points (SAPs) marked by circles. Each layer offers services through SAPs to upper layers. A service is defined by a
set of service primitives (operations) that a layer provides to upper layers. All physical functions such as spreading, modulation, multiplexing, mapping transport
channels to physical channels, etc., are located in layer 1. In the C-plane, layer 2 contains two sub-layers; MAC and RLC. In the U-plane, in
addition to MAC and RLC, two additional service dependent protocols exists; PDCPand BMC protocols. The main functions of MAC include mapping of logical channels onto transport
channels, priority handling between data flows and identification of UEs (userequipments) on common transport channels. The RLC main functions include ARQ,segmentation and reassembly and flow control.
PDCP exist only for packet switched domain services. It main function is headercompression.
BMC is used to transmit over the radio interface messages originating from cellBroadcast Centre (broadcast and multicast services).
Layer 3 consists of one protocol, RRC, which belongs to the control plane. Its mainfunction is to setup, modify and release layer 2 and layer 1 protocol entities. RRCmessages carry in their payloud also all higher layer signalling such as MM, CM andSM.
Gc, Nt and Dc are SAPs between RRC and higher layer protocols which are
independent of the access network.
-
7/31/2019 02 UTRAN Structure
11/44
UTRAN Channel
-
7/31/2019 02 UTRAN Structure
12/44
Definition of Channels
Logical Channel Type of information to be transmitted e.g., traffic or controllogical channels.
Transport Channel How and with what format data is transmitted through
physical links.
Physical Channel Unit of radio resource of a radio system e.g., frequency
band, time slot, code, etc.
RF Channel Fixed frequency band of a radio system.
The MAC sublayer is responsible for mapping logical channels onto transport
channels.
The physical layer is responsible for mapping transport channels onto physical
channels.
-
7/31/2019 02 UTRAN Structure
13/44
Logical Channels
Broadcast Control Channel (BCCH)
Paging Control Channel (PCCH)
Dedicated Control Channel (DCCH)
Common Control Channel (CCCH)
Control Channel (CCH)
Dedicated Traffic Channel (DTCH)Traffic Channel (TCH)
Common Traffic Channel (CTCH)
Interface between L2/MAC & upper layers
Classified by the transferred information
-
7/31/2019 02 UTRAN Structure
14/44
Transport channels
Common Channels (CCHs) Dedicated Channel (DCH)
(Uplink/Downlink)
Common PacketChannel(CPCH)(Uplink)
BroadcastChannel (BCH)
(Downlink)
Forward-Access
Channel (FACH)
(Downlink)
PagingChannel (PCH)
(Downlink)
Random-Access
Channel (RACH)
(Uplink)
Downlink SharedChannel(DSCH)(Downlink)
Interface between Physical Layer & L2/MAC
Classified by the transferred information & transfer methods on the physical layer
-
7/31/2019 02 UTRAN Structure
15/44
Transport ChannelsA common channel is a channel (resource) used by all users or a group of users in a cell. In the
downlink a common channel is a point-to-multipoint channel and in the uplink the channel iscontended by users.
A dedicated channel is a point-to-point channel allocated to a specific user.
BCCH is a downlink channel used to broadcast system and cell-specific information over the entirecell.
FACH is a downlink channel used to carry control information to a mobile station when the systemknows the location cell of the mobile station. FACH may also carry short user packets.
PCH is a downlink channel used to carry control information to a mobile station when the systemdoes not know the location cell of the mobile station. It is used to inform the mobile station of
incoming calls.
RACH is a uplink channel used to carry control information. It is used for initiating a call (initialaccess to the serving BS). RACH may also carry short user packets.
CPCH is a uplink channel used to carry infrequent medium sized packets.
DSCH is a downlink channel used to carry infrequent medium and large sized packets and can beshared in time between several users.
-
7/31/2019 02 UTRAN Structure
16/44
Mapping Logical Channels ontoTransport Channels
BCH PCH DSCHFACHRACH DCH
BCCH-
SAP
DCCH-
SAP
CCCH-
SAPPCCH-
SAP
DTCH-
SAP
Transport
Channels
MAC SAPs
USCH(TDD only)
CPCH(FDD only)
CTCH-
SAP
SHCCH-
SAP
(TDD only)
-
7/31/2019 02 UTRAN Structure
17/44
Uplink Physical channels
Common Physical ChannelsDedicated Physical Channels
Dedicated Physical Data Channels(Uplink DPDCH)
Dedicated Physical Control Channel
(Uplink DPCCH)) Physical Random Access Channel(PRACH)
Physical Common Packet Channel(PCPCH)
-
7/31/2019 02 UTRAN Structure
18/44
Downlink Physical Channels
Common Physical Channels
Dedicated Physical Channel (Downlink DPCH)A time multiplex of a downlink DPDCH and a downlink DPCCH
Common Pilot Channel
(CPICH)
Primary CPICH
Secondary CPICH
Primary Common ControlPhysical Channel(P-CCPCH)
Secondary Common ControlPhysical Channel(S-CCPCH)
SynchronisationChannel(SCH)
Physical DownlinkShared Channel(PDSCH)
Acquisition IndicationChannel(AICH)
Page IndicationChannel(PICH)
-
7/31/2019 02 UTRAN Structure
19/44
Mapping Transport Channels ontoPhysical Channels
BCH FACH PCH RACH DCH DSCH
P-CCPCH
S-CCPCH
PRACH
Transport
channels
CPCH
Physical
channelsAICH
PICH
PDSCH
SCH
DPCCH
DPDCH
PCPCHCPICH
-
7/31/2019 02 UTRAN Structure
20/44
RACH Procedure I
Access Preamble
Control Part
Data Part
Message Part
4096 chips
Structure of the random access transmission
0P 1PjP
1,2)(Nmsec10*N
-
7/31/2019 02 UTRAN Structure
21/44
RACH Procedure II
The MS receives from the BCH the available sub-channels(Access slots), scrambling codes and signatures.
The MS selects randomly one of the RACH sub-channelsfrom the group its access class allows it to use. It alsoselects a signature randomly from the available signatures.
A 1 ms access preamble is transmitted using the selectedsignature.
The MS monitors the Acquisition Indication Channel (AICH)to see whether the BS has received the preamble.
If no AICH is detected, the MS increases the accesspreamble transmission power by a fixed amount given by theBS and transmits it again in the next available access slot.
When an AICH is detected, the MS transmits the 10 ms or 20
ms massage part of the RACH.
-
7/31/2019 02 UTRAN Structure
22/44
RACH Procedure III
Data bitsNdata
Control
slotT 0..3)(kbits2*10chips,2560 k
Slot 0 Slot 1 Slot i Slot 14
ms10TframeradiopartMessage RACH
Structure of the random-access message part
bitsNdata TFCIN
Data
Pilot
bits
TFCI
-
7/31/2019 02 UTRAN Structure
23/44
CPCH Procedure I
Access Preamble
Collision ResolutionPreamble
Control Part
Data Part
Message Part
4096 chips
Structure of the CPCH random access transmission
0P P1jP jP
msec10 msec10*N
-
7/31/2019 02 UTRAN Structure
24/44
CPCH Procedure II
It is similar to the RACH procedure. The main differenceis the Collision Detection (CD) which has a similarstructure to that of the access preamble.
The operation follows the RACH procedure until the MS
receives the AICH. After that a CD preamble with thesame power level using a different signature is sent tothe BS. On the receipt of this preamble, the BS thensends back a CD-Indication Channel (CD-ICH).
After the MS receives the correct CD-ICH, it transmits
the message which may last over several frames. The use of a CD preamble reduces the probability of
collision on layer 1.
-
7/31/2019 02 UTRAN Structure
25/44
Dedicated Physical Channels (DPCH)
DPDCH
DPCCH
Dedicated Physical Data Channel
Dedicated Physical Control Channel
DPDCH - Carries dedicated transport channels
DPCCH - Carries control information at layer 1 ( known pilot,transport format combination indicator (TFCI) feedbackinformation (FBI) and transmit power control (TPC)
command
DPCH
The pilot bits are used for channel estimation in the receiver.The TPC bits carry the power control commands.The FBI bits are used when closed loop transmission diversity is used in the downlink.The TFCI indicates the transport format of the DPDCH in the same frame.
-
7/31/2019 02 UTRAN Structure
26/44
DPDCH
bitsNdata
bitsNdata
bitsNTFCI bitsNFBI bitsN TPCDPCCH
slotT 0..6)(kbits2*10chips,2560k
Frame structure for uplink DPDCH/DPCCH
ms10T:frameradio1 f
Slot 0 Slot 1 Slot i Slot 14
Data
Pilot TFCI FBI TPC
Uplink DPCH Procedure I
-
7/31/2019 02 UTRAN Structure
27/44
Uplink DPCH Procedure IITransmission time is divided into radio frames. The size of a radio frame is 10
ms consisting of 15 time slots.
One time slot corresponds to 2560 chips (0.667 ms), which equals to onepower control period.
DPDCH and DPCCH bits transmitted in parallel in each time slot using I and Qstreams of QPSK modulation. i.e., one QPSK symbol (phase) carries one bit ofDPDCH and one bit of DPCCH (I-Q/code multiplexing).
DPDCH carries the traffic and/or signalling (control information of higher layers.
DPCCH carries the physical layer control information (pilot, TFCI, FBI and TPCbits).
DPCCH uses a fixed spreading factor of 256. i.e., 10 bits per time slot.
DPDCH uses 7 spreading factors from 256 to 4. No. of bits per time slot can becalculated from 10 * 2 k where k = 0, , 6.
-
7/31/2019 02 UTRAN Structure
28/44
The DPDCH and DPCCH are spread to a fixed chip rate of 3.84 Mchips/s bythe channelization codes, Cd and Cc, respectively.
The DPDCH uses Cch,SF,k code where SF is the spreading factor (256 to 4)and k is the branch no. of the code tree for the same SF (k = 0, , SF-1). The
value of k = SF/4 is used for the DPDCH.
The DPCCH uses Cch,256,0 i.e., the top branch of the code tree for SF = 256.Bd and Bc are gain factors used to adjust the relative transmitted power of theDPDCH and DPCCH.
Slong, n or Sshort, n is the scrambling code for nth mobile station. The mobilestation is identified by its scrambling code.
One DPCCH and up to six parallel DPDCHs can be transmittedsimultaneously.
Uplink DPCH Procedure III
-
7/31/2019 02 UTRAN Structure
29/44
All uplink physical channels are subjected to scramblingwith a complex-valued scrambling code.
The DPCCH/DPDCH may be scrambled by either long orshort scrambling codes.
The long scrambling codes are from a set of Goldsequences of 38400 chips. There are 224 long uplinkscrambling codes.
The short scrambling codes are derived from a sequenceof the family of periodically extended S(2) codes. There are 224 shortuplink scrambling codes.
Uplink scrambling codes are assigned by higher layers.
Uplink Scrambling Codes
-
7/31/2019 02 UTRAN Structure
30/44
Downlink DPCH Procedure I
bitsNdata1 bitsNTPC bitsNdata2 bitsNPilot
slotT 0..7)(kbits2*10chips,2560k
Slot 0 Slot 1 Slot i Slot 14
ms10T:frameradioOne f
bitsNTFCI
DPDCH DPCCH DPDCH DPCCH
Frame structure for downlink DPCH
Data1 TPC TFCI Data2 Pilot
-
7/31/2019 02 UTRAN Structure
31/44
Downlink DPCH Procedure II
Time multiplexing of the DPDCH and DPCCH isused in the downlink.
In the downlink the spreading factors range from4 to 512, with some restrictions on the use ofspreading factor 512 in the case of softhandover.
The downlink DPDCH consists of QPSK
symbols. Each symbol consists of two bits whilein the case of uplink the DPDCH consists ofBPSK symbol (one symbol corresponds to onebit).
-
7/31/2019 02 UTRAN Structure
32/44
A total of 2181 scrambling codes can be generated.however, only 8192 of these scrambling codes are used.
The scrambling codes are divided into 512 sets each of aprimary scrambling code and 15 secondary scrambling codes.
The downlink scrambling codes are segments of a different setof the Gold sequences.
The scrambling codes are repeated for every 10 ms radioframe.
Downlink Scrambling Codes
-
7/31/2019 02 UTRAN Structure
33/44
SCH Procedure I
Tf = 15 x Tslot
Tslot
Primary SCH
Secondary SCH
cp Primary Synchronisation Code ( It is the same for every cell in the system)
csi,k Secondary Synchronisation Codes ( Where i=0,1.63 is the number of the scrambling
code group, and k= 0,1,14 is the slot number. Each code is chosen from a set of16 different codes of length 256).
pc
sci, 0
pc
i, 2 sc i, 14
256 chips2560 chips
sc
pc
-
7/31/2019 02 UTRAN Structure
34/44
The synchronisation channel consists of two channels, the primaryand secondary synchronisation channels.
The primary SCH uses a code of 256 chips transmitted over everyslot.
The primary SCH code is the same for every cell in the system. The primary SCH is used for slot synchronisation. The secondary SCH consists of 64 sequences, each sequence has
a 15 code of length 256 chips. Each BS transmits a specificsequence in every frame (one code per time slot), repeatedly.
Each code sequence is associated to one downlink scrambling codegroup. The secondary SCH is used for frame synchronisation.
SCH Procedure II
-
7/31/2019 02 UTRAN Structure
35/44
RRC Service States
-
7/31/2019 02 UTRAN Structure
36/44
RRC Service States
-
7/31/2019 02 UTRAN Structure
37/44
RRC Service States
-------- Idle Mode
-
7/31/2019 02 UTRAN Structure
38/44
RRC Service States
-------- Cell_DCH State
-
7/31/2019 02 UTRAN Structure
39/44
RRC Service States
-------- Cell_FACH State
Cell Broadcast (CB)
SMS CB Service (CBS)
-
7/31/2019 02 UTRAN Structure
40/44
RRC Service States
-------- Cell_PCH State
-
7/31/2019 02 UTRAN Structure
41/44
RRC Service States
-------- URA_PCH State
-
7/31/2019 02 UTRAN Structure
42/44
UE-initiated RRC state transition
-
7/31/2019 02 UTRAN Structure
43/44
Network-initiated state transition
-
7/31/2019 02 UTRAN Structure
44/44
For latest changes to the UTRAN standard,please see:
www.3gpp.org
Particularly,
TS 25.211 to TS 25.214 V3.1.1 (2000-03)For FDD modeTS 25.221 to TS 25.224 V3.1.1 (2000-03)For TDD mode
top related