Presentation on theme: "1 Purpose Introduce IS-2000 in terms of basic features or capability supported Standard is not organized by features, but rather they are largely hidden."— Presentation transcript:
1 Purpose Introduce IS-2000 in terms of basic features or capability supported Standard is not organized by features, but rather they are largely hidden in specification wording Assuming knowledge of IS-95 Focus on differences and enhancements from IS-95 A high-level description intended for internal and external audiences
2 Third Generation (3G) Terms and Conventions Spreading Rate Spreading Rate 1 (1x) Forward and Reverse Channels use DSSS carrier at 1.2288Mcps Spreading Rate 3 (3x) Forward Channel uses three DSS carriers at 1.2288Mcps each Reverse Channel uses one DSSS carrier at 3.6864Mcps RTT: Radio Transmission Technology Collection of air interface technologies for telecommunication systems 1xRTT EV-DV: RTT: Radio Transmission Technology EV: 1xEVolution is the migration path of 1x systems to higher packet data rates DV: Data and Voice 3GPP2: 3G Partnership Project 2 Collaboration of many Standards Development Organizations Global specifications for IS-41 based networks
3 Goals for 3G CDMA Backward compatible to IS-95 Enhanced Wireless Services Voice Circuit Switched Data Packet Switched Data Double the voice capacity Data rates up to 2Mbps
4 CDMA 2000 Family of Standards Release 0 – Completed 7/1999 First 3G CDMA specification Completed under a tight schedule Not all physical layer features are supported by the signaling specification of Release 0 Today’s CDMA 1x typically offer up to 153kbps data rate, upload and download Release A – Completed 3/2000 Contain signaling support for the entire Release 0 physical layer Technically, Release A is the first complete 3G CDMA air interface specification Most people consider Release 0 as the baseline 3G standard today
5 CDMA 2000 Family of Standards Release B A small release that served the purpose to timely introduce some urgent carrier requirements Release C – Completed 5/2002 1x EV DV (1xRTT Evolution, Data and Voice) was first introduced Allows up to 3.1Mbps on the forward link Release D DV reverse link improvement Close to completion
6 1x EV DO (1xRTT Evolution, Data- Only) A separate series of specification that belongs to the CDMA2000 family of standards – (IS- 856) A completely different air interface standard but operate on the same 1xRTT spectrum Both 1x and 3x are included in IS-2000, although 3x is becoming obsolete and no longer of interest to any carriers Different than 1x EV DV, it requires a complete 1.25MHz CDMA carrier Baseline 1x EV DO spec was published in 2001 A new release, namely 1xEV DO Release A is currently under going standardization, targeting major reverse link improvements
7 CDMA2000 versus WCDMA Even though both are based on CDMA technology they are significantly different: Spreading rate is 3.84Mcps (versus 1.2288Mcps) BS not Synchronized to GPS time Core network is GSM MAP based (versus ANSI-41) Vocoders are different
8 Agenda CDMA2000 Protocol Layers Air Interface Physical Layer Data Multiplexing Power Control Enhancements Rel. C Features
9 CDMA 2000 Protocol Layers IS-95 mixes layers CDMA 2000 separate different layers One of the most visible feature from the specification itself Architecture impact to implementation CDMA 2000 Layers PHY: Physical Layer- cdma2000 volume 2 MAC: Medium Access Layer- cdma2000 volume 3 LAC: Link Access Layer- cdma2000 volume 4 L3: Layer 3 Signaling- cdma2000 volume 5
11 Agenda CDMA2000 Protocol Layers Air Interface Physical Layer Logical and Physical Channel Naming New Physical Channels Radio Configurations Variable Walsh Spreading Quasi-Orthogonol Codes Turbo Coding 5 ms Frame Support Modulation Differences Data Multiplexing Power Control Enhancements Rel. C Features
12 Logical vs. Physical Channels Forward Link and Reverse Link Forward Link: BS to MS, written in f- or F- Reverse Link: MS to BS, written in r- or R- Logical Channels Always written in lower case csch: common signaling channel, include f-csch and r-csch Signaling channel shared by more than one MS dsch: dedicated signaling channel, include r-dsch and f-dsch Signaling channel assigned to one MS dtch: dedicated traffic channel, include f-dtch and r-dtch All traffic channels, prior to Rel D, are usually dedicated to one user/MS Physical Channels Expressed in capital letters
13 Physical Channels Naming – Common Channels Forward Common Channels F-PICHPilot channel, same as IS-95 F-SYNCSync Channel, same as IS-95 F-PCHPaging Channel, same as IS-95 F-CCCHCommon Control Channel F-BCCHBroadcast Control Channel F-CACHChannel Assignment channel F-CPCCH Common Power Control channel F-QPCH Quick Paging channel F-TDPICH Tx Diversity Pilot channel F-APICH Dedicated Auxilary Pilot channel R-ATDPICH Aux Tx Diversity Pilot channel Reverse Common Channels R-ACHAccess Channel, same as IS-95 R-PICHReverse Pilot channel R-CCCHReverse Common Control channel R-EACHReverse Enhanced Access channel
15 Logical to Physical Channel Mapping MAC function maps logical channels with one or more physical channels Dedicated channels are setup for each call
16 New Physical Channels: Reverse Link Pilot Channel R-PICH is used by the BS receiver to estimate the carrier phase and perform pilot added coherent demodulation Increase in Reverse Link Capacity The IS-95 reverse link transmission is based on non-coherent detection R-PICH can be used to estimate the energy of the received traffic channel and to perform reverse link inner loop power control
17 New Physical Channels: Forward Link Transmit Diversity Transmit Diversity increases the Forward Link Capacity since a lower E b /N 0 is required Transmit Diversity reduces the effects of deep fades since each path is separated in space or time; requires two antennas Two methods are optionally provided for: Space Time Spreading (STS) Transmit Diversity Uses an orthogonal subsequence so that all symbols are transmitted on both antennas Orthogonal Transmit Diversity (OTD) Splits the symbols into two streams. Each stream is spread with a different Walsh sequence and transmitted via a different antenna. OTD auxiliary pilot is required to support the second antenna – not expected to be used
18 New Physical Channels: Quick Paging Channel QPCH is introduced to decrease the wake time of a MS in slotted mode, that is the time the MS has to periodically demodulate the PCH or F-CCCH. Increase MS battery life MS monitors Paging Indicators on an assigned QPCH slot based on its IMSI. The QPCH slot proceeds its assigned PCH slot by 100 ms. BS sets the PI bit to the ‘ON’ state to inform the MS that it should receive the F-CCCH or PCH in the next slot Compared with demodulating 1 or 2 80ms PCH/F-CCCH frame Tradeoff: Requires additional Forward Link Channel and may introduce signaling latency
19 New Physical Channels: Access Channel Enhancements Four new physical channels: R-EACH, R-CCCH, F-CACH and F- CPCCH were introduced to support four different types of new access modes on top of the basic IS-95 access methods. 1.Basic Access (BA) mode is mandatory R-EACH is required for this mode 2.Reservation Access (RA) mode is mandatory R-EACH, R-CCCH, F-CACH and F-CPCCH are required for this mode 3.Power Controlled Access (PCA) mode (Rel. B) R-EACH, F-CACH and F-CPCCH are required for this mode 4.Designated Access (DA) mode (Rel. B) R-CCCH, F-CCCH and F-CPCCH are required for this mode Access Channel Enhancements reduces probability of packet collision.
20 New Physical Channels: New Traffic Channels Three new dedicated traffic channels: FCH, DCCH and SCH. All traffic channels are code multiplexed. The independent gain settings and QoS requirements such as FER or BER on the traffic channels can be set independently for optimal allocation of link resources. Benefits: Compared to IS-95, IS-2000 Dedicated Traffic Channels allow flexible support of different services in a more efficient manner. SCH allows the transport of scheduled high speed data. DCCH allows better voice quality for premium voice services and can reduce packet scheduling delay.
21 New Physical Channels: New Traffic Channels The FCH supports variable-rate transmission with blind rate detection Maximum data rate is 9.6 or 14.4 kbps for Rate Set 1 or 2 The SCH is used to carry data traffic in circuit or packet mode SCH data rate is a multiple (1x, 2x, 4x, 8x, or 16x) of the fundamental data rate used by the corresponding FCH or DCCH, that is, either 9.6 or 14.4 kbps for Rate Set 1 or 2, respectively. The data rate of the SCH must be scheduled using signaling, unlike the FCH that employs variable-rate transmission with blind rate detection. DCCH is a dedicated channel for signaling and mini-signaling messages directed to a particular user Can be in Discontinuous Transmission Mode (DTX) when no signaling data is to be sent Possible to share the same F-DCCH for multiple mobiles on time- shared basis to conserve the Walsh Code resource Although DCCH may also carry regular voice or data traffic, it should typically be reserved for signaling
22 New Radio Configurations Radio Configurations (RC) are introduced to specify a given code rate, modulation, and spreading rate. The IS-95 Rate Set 1 and Rate Set 2 replaced by Radio Configurations for Forward and Reverse Links. Forward Link: RC 1-5 for 1x and RC 6-9 for 3x Reverse Link: RC 1-4 for 1x and RC 5-6 for 3x Forward Link Radio Configurations * per Supplemental Channel C= Convolutional, T = Turbo RCRS Max Data Rate* ~kbps FEC Rate FEC Encode Modulation 119.61/2CBPSK 2214.43/4CBPSK 31153.61/4 C or T QPSK 41307.21/2 QPSK 52230.43/8 QPSK
23 New Radio Configurations Reverse Link Radio Configurations * per Supplemental Channel C= Convolutional, T = Turbo The requirements to support IS-2000 RC are as follows: IS-95 compatible mode: F/R (1,1) and (2,2) 1x cdma2000 mode: F/R (3,3), (4,3), and (5,4) RCRS Max Data Rate* ~kbps FEC Rate FEC Encode Modulation 119.61/3C 64-ary ortho 2214.41/2C 31153.61/4 C or T QPSK 31307.21/2 QPSK 42230.43/8 QPSK
24 Walsh Code Notation and Generation Walsh codes generated using tree structure: Walsh code W i m represents a Walsh code of length m using index I IS-95 uses length 64 Walsh Codes cdma2000 uses variable length Walsh Codes with base rate 128 (W i 128 )
25 Variable Length Walsh Codes Variable length Walsh spreading achieves higher data rates on the forward link Assigning a shorter Walsh function to a user while increasing the data rate results in a constant chip rate Shorter codes are higher up in the tree structure, longer codes generated from this code can not be used at the same time (maintain orthogonality between channels) Improved Walsh resource utilization: Certain code channels such as the Auxiliary pilot may be spread using a long Walsh function, which can enlarge the set of Walsh resources
26 Variable Length Walsh Codes Some cdma2000 Forward Link Channel Walsh Codes Forward Pilot W 0 64 Quick Paging Channel W 80 128 Transmit Diversity Pilot W 16 128
27 Quasi-Orthogonal Function (QOF) Forward Link may run out of Walsh code space Increased capacity improvements Additional overhead channels Variable Walsh code spreading Quasi-Orthognoal Function can be used to enlarge the number of code channels Generated by multiplying Walsh Codes by masking functions with QPSK symbols. QOF’s are not orthogonal to the Walsh space but are close to orthogonal (“Quasi”). QOF is mandatory for IS-2000 mobiles. A 2-bit QOF field is added in Extended Channel Assignment (ECAM) and Universal Handoff Direction Message (UHDM) to support QOF assignment
28 Turbo Codes Turbo codes require lower Eb/No than traditional convolutional codes at a high rate – Increased capacity! In IS-2000 turbo codes can be used on SCHs, typically when the data rate 19.2 kpbs Turbo codes generated using two parallel convolutional encoders with an interleaver before the second encoder Turbo decoding usually requires long processing delay and is used for delay-tolerant packet data services
29 Support of 5 ms frames Shorter frame sizes allows faster signaling between MS and BS 5ms mini frames can be operated on FCH, DCCH, or some of the common channels such as F-CCCH and R-CCCH 5ms frames are intended to carry small signaling messages that require a fast turn around time For example, the mini-PPSMM message, Supplemental Channel Request Mini Message (SCRM), Forward/Reverse Supplemental Channel Assignment Mini Message (SCAM), etc. The 5ms frame support is optional for MS and BS
30 Physical Layer Modulation Differences Forward Link Differences True QPSK using Complex Spreading on I and Q channel More robust to mitigate interference Reverse Link Differences IS-95 Reverse Link is either Access or Traffic channel cdma2000 transmits multiple channels simultaneously Each channel assigned either I or Q path Each channel can have different rates and power levels Walsh sequences separate physical channels Complex Spreading on I and Q channel No PCG power gating as with IS-95
31 Agenda CDMA2000 Protocol Layers Air Interface Physical Layer Data Multiplexing Power Control Enhancements Rel. C Features
32 Radio Access Bearer Profile Support RAB: A service connection with a BS MAC controls profile of RAB assigned to a single user MAC also control logical to physical mapping Even though multiple service options may be connected between the Core Network and the MS, each of them corresponding to a RAB, MAC may still map two or more bearers onto a single physical channel LPM (Logical to Physical Channel Mapping) Key for supporting complex services such as Concurrent Services for multimedia applications (e.g. parallel voice and video streams).
33 RABs supported by CDMA2000 V1 (Voice Option 1): Signaling and Voice on FCH V2 (Voice Option 2): Voice on FCH; Signaling on DCCH P1 (Packet Option 1): Signaling and Data on FCH; Data Bursts on SCH P2 (Packet Option 2): Signaling and Data on DCCH; Data Bursts on SCH P3 (Packet Option 3): Data on FCH; Signaling on DCCH; Data Bursts on SCH VP1 (Voice and Data Option 1): Signaling, Voice, and Data on FCH; Data Burst on SCH VP2 (Voice and Data Option 2): Signaling and Voice on FCH; Data on DCCH; Data Burst on SCH CH (Control Hold Mode): Only Reverse Pilot Tx (reduced power) Power Control is on FCH if present, DCCH otherwise Power Control is on FCH if present, DCCH otherwise
34 Bearer Profile Support Requirements Requirements: V1: Mandatory for MS and BS V2: Optional, but Mandatory if DCCH is supported P1: Optional, but Mandatory if SCH is supported P2: Optional, but Mandatory if both DCCH and SCH are supported VP1: Optional, but Mandatory if SCH is supported and Concurrent Services is supported P3, VP2: Optional for MS and BS VoiceDataDV Signaling Only FCH only V1P1VP1X DCCH only XP2XCH FCH + DCCH V2P3VP2X
35 IS-2000 Data Multiplexing Traffic Types Primary Traffic: User Voice Secondary Traffic: User Data other than Voice Signaling: Call Control Messaging Mode A: IS-95 compatible FCH for signaling and primary and/or secondary traffic Up to 7 SCCH channels for Medium Data Rate (MDR) Mode B: cdma2000 enhancement FCH and/or DCCH for signaling and primary and/or secondary traffic Up to 2 SCH channels for High Speed Data (HSD) FCH Dim-and-Burst and Blank-and-Burst Primary Traffic Only Dim-and-Burst Rate: 1/2, 1/4, 1/8 division of Primary traffic and Signaling or Secondary traffic Blank-and-Burst: Signaling Only
36 IS-2000 Data Multiplexing Multiplexing: Tx and Rx function routing under QoS priorities RLP: Radio Link Protocol for segmentation and reassembly of packets (IS-707A)
37 RLP Types Type 1: Rate Set 1 (9600 bps) FCH supports full, 1/2, 1/4, 1/8 rate DCCH, SCH, SCCH supports full rate Type 2: Rate Set 2 (14400 bps) FCH supports full, 1/2, 1/4, 1/8 rate DCCH, SCH, SCCH supports full rate Type 3: Used on SCH to select RS, block size, and rate multiplier (19.2 kbps to 230.4 kbps) Type 4: Used on FCH and DCCH supporting 5ms for signaling Type 5: Used on SCH, single service data only, variable length Type 6: Used on FCH and DCCH, multiple services
38 Logical Transmit Unit (LTU) Processing LTU: Logical Transmission Unit Split higher rate frames into sub-frames (LTU) with their own CRCs inserted at the MAC layer. Physical layer frame is the same regardless of number of LTUs When LTUs processing is used and the physical frame is received in error, the multiplexing sublayer will perform CRC checking on a per LTU basis and may be able to recover one or more LTUs More efficient than discarding the entire frame in error
39 MuxType for RLP Type 3 Data Service Negotiation between MS and BS results in time limited bandwidth reservation Above tables applies per SCH (0/1) SCH Rate Rate Set 1 Rate Set 2 SingleDoubleSingleDouble 2x2x2x2x 0x809 0x905 0x80a 0x906 4x4x4x4x 0x811 0x909 0x812 0x90a 8x8x8x8x 0x821 0x911 0x822 0x912 16x 0x921 0x922 SCH Rate Rate Set 1 Rate Set 2 1x1x1x1x 9600 bps 14400 bps 2x2x2x2x 19200 bps 28800 bps 4x4x4x4x 38400 bps 57600 bps 8x8x8x8x 76800 bps 115200 bps 16x 153600 bps 230400 bps
40 Agenda CDMA2000 Protocol Layers Air Interface Physical Layer Data Multiplexing Power Control Enhancements Rel. C Features
41 Fast Forward Link Power Control Major contributor to increased capacity (2x voice capacity) by decreasing the overall interference on the Forward Link In IS-2000 the forward link dedicated traffic channels (FCH, DCCH, SCH) can be jointly power controlled at a rate of up to 800 Hz ‘Up’/’Down’ power control bits in 1dB, 0.5dB, or 0.25dB The power control information bits are carried over the reverse power control subchannel, which is time multiplexed with the Reverse Link Pilot Channel
42 Fast Forward Link Power Control Modes Five forward link power control modes in Release 0, plus two more modes added in Release A Mode 0x00: The reverse power control subchannel is entirely dedicated to either the forward FCH or DCCH The power control subchannel rate is in this case equal to 800 Hz Each traffic channel frame carries 16 power control groups Mode 0x01 or 0x10: Two reverse power control subchannels are time multiplexed The primary subchannel controls either the forward FCH or DCCH, while the secondary subchannel controls the SCH. Primary and secondary can be both operated at 400 Hz, or can be operated at 200 and 600 Hz, respectively. Mode 0x11 or 0x100: The power control subchannel bits are all set equal to the Erasure Indicator Bit (EIB) or the Quality Indicator Bit (QIB), therefore slowing down the effective rate of the power control subchannel to 50 Hz. Mode 0x11: Equivalent to the power control method used in IS-95B Rate Set 2 transmission
43 Fast Forward Link Power Control Modes Mode ‘101’ (Rel A): MS uses the QIB definition with 800 bps feedback on the Reverse Power Control Subchannel are grouped into 50, 25, or 12.5 bps depending on the frame length of that F-SCH. Mode ‘110’ (Rel A): MS maintains a 400 bps feedback on the F-FCH or the F-DCCH (similar to FPC_MODE = ‘001’) Remaining 400 bps are grouped into 50, 25, or 12.5 bps feedback to send the EIB (similar to FPC_MODE = ‘011’) on the master F-SCH The BS gains much faster feedback on the true quality of the F-SCH without incurring much signaling load
44 Enhanced Reverse Link Open Loop Power Control IS-95B uses fixed power estimate parameters for R-FCH IS-2000: the R-PICH open loop power control is specified, and each code channel output power for the reverse traffic channels are set relative to the pilot channel BS controls power levels on per call basis Allows the most reliable call setup balanced with reverse link network capacity
45 Agenda CDMA2000 Protocol Layers Air Interface Physical Layer RLP Type 3 and Multiplex Options Power Control Enhancements Rel. C Features
46 Fundamentals of EV-DV 1x Evolution to Data and Voice (1xEV-DV) Single 1.25 MHz bandwidth shared between voice and data users 3.1 Mbps peak data rate on Forward Packet Data Channel (F- PDCH) Voice users are usually scheduled first Dynamic allocation of the unused BS power to data users every slot cycle (1.25 ms)
47 Some Details EV-DV scheduler controls the allocation of Walsh space and BS power based on user traffic type (voice, ftp, http, etc.), buffer size and channel conditions MS monitors and reports its channel condition (C/I) every 1.25 ms
48 Major Feature Enhancements 3.1 Mbps data rate on Forward Packet Data Channel (F-PDCH) Two Forward Packet Data Control Channels (F- PDCC0/1) to support F-PDCH operations Two Reverse Control Channels (R-CQICH and R- ACKCH) to provide scheduler feedback Adaptive Modulation and Coding (AMC) BS rate control based on MS channel conditions Hybrid ARQ using Autonomous Adaptive Incremental Redundancy (AAIR)
49 Dynamic Link Adaptation Variable parameters = transmit power, modulation, code rate, packet length (1, 2, 4 slots), Walsh space BS receives C/I values from each MS Uses C/I and current BS load to decide transmit parameters If mobile is able to successfully decode the PDCH it sends an ACK on the ACK channel If NAK sent, packet will be re-transmitted using HARQ* (AAIR - Autonomous Adaptive Incremental Redundancy) Up to 4 HARQ channels in parallel to reduce latency HARQ combines information from previous transmission (not a simple re-transmission) * Hybrid Automatic Retransmission and Queing
53 Terms and Conventions, Acronyms Acronyms ARQAutomatic repeat request BSBase Station CNCore Network EAPEnhanced access probe ECAMExtended Channel Assignement Message FERFrame Error Rate FFPCFast Forward Link Power Control L3Layer 3 LACLink access control LTULogical transmit unit MACMedia access control MABOMobile Assisted Burst Operation MAHOMobile Assisted Hard Handoff MSMobile Station MUXMultiplexing OTDOrthogonal transmit diversity PDUProtocol data unit PCPower Control QOFQuasi orthogonal function
54 Terms and Conventions, Acronyms Acronyms QoSQuality of Service RTTRadio transmission technology RsMAReservation Mode Access SARSegmentation and reassembly SDUService data unit SR1Spreading rate 1 (i.e. 1x) SR3Spreading rate 3 (i.e. 3x)
55 Features discussed Radio Access Bearer Profiles Advanced Packet Data States Control IS-2000 Multiplexing IS-2000 Quality of Service (QoS) Radio Link Protocol (RLP) Type 3 Fast Forward Link Power Control Secondary Power Control Subchannel Enhanced Reverse Link Open Loop Power Control New Radio Configurations Variable Length Walsh Codes Logical Transmit Unit (LTU) Processing Reverse Link Pilot Channel Auxiliary Pilots Quick Paging Channel (QPCH) IS-2000 New Traffic Channels (FCH, DCCH and SCH) Orthogonal Transmit Diversity (OTD) Space Time Spreading (STS) Transmit Diversity (A)
56 Features discussed Multiple Frame Interleaving Turbo Codes Quasi-Orthogonal Function (QOF) Support of 5 ms frames Short Data Burst Teleservice Mobile Assisted Burst Operation Mobile Assisted Hard Handoff Enhancements User Feature Enhancements Access Channel Enhancement (A) Paging Channel Enhancements (A) Enhanced Encryption (A) Flexible Rate (A) Variable Rate Supplemental Channel (A) Settable Reverse Link Power Control Loop Delay (A) Power Boosting for Inter-Frequency HHO Search(A)
57 Features discussed FCH 1/8th Rate Gating (A) CDMA Tiered Services (A) Concurrent Services (A) Diversity Code Combining in Soft Handoff (B) New Repetition Scheme for Flexible and Variable Rate (B) Call Type Based Access Control (B)
58 Auxiliary Pilots May be used for spot beam and adaptive antenna applications Obtain channel estimation for coherent detection on the forward link when mobiles are in the spot beam coverage or being tracked by smart antennas. Support of this feature requires one or more code-multiplexed auxiliary pilots with each antenna beam At the upper layer, an auxiliary pilot is treated the same as a regular pilot. Benefits: Beam forming and adaptive antenna can increase capacity and performance Antenna beam-forming can extend the range of voice terminals in difficult conditions and/or increase the supported data rate for high speed mobiles
59 Paging Channel Enhancements IS-2000 supports BCCH and F-CCCH as part of enhanced forward common control channel. The physical layer specification of BCCH and F-CCCH were introduced in Release 0 but the signaling support was not completed until Release A. In IS-95, only one common control channel, Paging Channel, is used for both broadcast and mobile directed page messages. Two common control channels allows optimizing the physical layer structure (frame length and bit rate), the BS transmission power (based on the type of message to be carried and its requirements, e.g., short latency, high reliability), and the scheduling of paging message transmission. If the BS supports the IS-200-A common channels, that the minimum configuration shall include the BCCH, F-CCCH, and the R-EACH.
60 Paging Channel Enhancements BCCH Operation: Rate: 4.8, 9.6, or 19.2 kbps. At lease one primary BCCH when supported. The primary BCCH is used to carry the overhead information. There can also be more BCCHs, for example, to carry broadcast SMS. Number of additional BCCH and their transmission rate are defined in the Extended System Parameters Message. The MS determines from the General Neighbor List Message whether or not the target BS supports the BCCH operations. F-CCCH Operation can be operated at 9.6, 19.2, or 38.4 kbps and carry 5, 10, and 20ms frames. Different from the IS-95 PCH, there can be one or more F-CCCH designated as the primary F-CCCH and/or the secondary F-CCCH.
61 MS periodically monitors the primary F-CCCH, using similar slotted or non-slotted mode. The primary F-CCCH is used to transmit those messages for which the MS location is not yet known, such as the General Page Message, therefore using either flood or zone-based paging. The primary F-CCCH is operated at a constant rate, which can be 9.6, 19.2, or 38.4 kbps, as advertised by some overhead message on the primary BCCH. All others messages for which the MS location is known (e.g., those that are transmitted after the BS receives the Page Response or Origination Message ) are transmitted on the secondary F-CCCH. Another fundamental difference of the F-CCCH with respect to the PCH is that the secondary F-CCCH can be operated in soft handoff. Soft handoff may greatly improve demodulation performance for those messages, such as the Extended Channel Assignment Message, that require high reliability and low latency (ARQ cannot be used) requirements
62 MS directed messages sent on the secondary F-CCCH can be transmitted at a power level that depends on the estimated MS to BS path loss, therefore reducing forward link capacity consumption. The capacity advantage may be considerable since the vast majority of the messages are sent on the secondary F-CCCH Benefits The F-CCCH can be used to transmit short (5 or 10ms) messages in support of low-latency signaling for packet data or multimedia services, or can be used to transmit long data bursts at high rate in support of a wide variety of data services. The BCCH allows an idle mode MS to decrease the time spent awake while updating the overhead information. The total power allocated to both the BCCH and F-CCCH may be smaller than the one allocated to the PCH. The use of the secondary F-CCCH with power/rate control capability contributes to the forward link capacity improvement. Operation of the F- CCCH in soft handoff also improves forward link capacity.
63 Multiple Frame Interleaving IS-2000A allows the over-the-air frames of duration equal to 20, 40, or 80 ms. Motivation: by increasing the time span of the physical layer frame interleaver, better demodulation performance may be achieved. Performance gain depends on the encoder type, rate, and channel conditions. Note: benefits in capacity/throughput, but can also introduce larger delay, and therefore is limited for the SCH only. RCs supporting multi-frame interleaving are RC3 and RC4 for spreading rate 1, and RC6 and RC7 for spreading rate 3. BS uses the Service Configuration Record in the Service Connect Message or Universal/General Handoff Direction Message to convey the frame duration information.
64 Multiple Frame Interleaving, #2 Frame Offset Adjustment due to multi- frame interleaving: increased from 4 bits to 6 bits, 4 bits for pcg-level offset and 2 bits for frame level offset. First 4 bits correspond to FRAME_OFFSET, in units of 1.25 ms, same as that for DCCH or FCH. The second 2bits are set to FOR_SCH_FRAME_OFFSET, in units of 20 ms, which is used to stagger the longer SCH frames. 20 ms staggering is necessary because the 1.25 ms increment, depending on the internal BS transport network bandwidth, may not be sufficient when the SCH is transmitted at very high rate or when the load of the BS internal transport network has already peaked.
65 Short Data Burst Teleservice Short Data Burst Teleservices (SDB) allows a MS to send or receive a data burst while in dormant or control hold state, without the overhead of setting up any traffic channel. On the network side, SDB-enabled packet data infrastructure may avoid the overhead of setting up the traffic bearer by sending small block of packets over the already established control channel. SDB is optional for MS and optional for BS. However certain carriers may require this feature to support special applications. Note that a SDB_DESIRED_ONLY field has been added to Release B to allow more flexible use of SDB for small data bursts on the common control channel. SDB is optional for MS and optional for BS. However certain carriers may require this feature to support special applications. Note that a SDB_DESIRED_ONLY field has been added to Release B to allow more flexible use of SDB for small data bursts on the common control channel. Benefits SDB can be an efficient way to support certain data applications.
66 Mobile Assisted Burst Operation Mobile Assisted Burst Operation (MABO) allows an MS to report the pilot strengths of the Active Set relatively quickly and frequently during high rate Supplemental Channel data bursts or burst on the enhanced access channels. A mini PSMM (Pilot Strength Measurement Mini Message) messages have been added to the Reverse Traffic Channel. The BS controls the rules (configurable by the BS via signaling) that trigger the mini PSMM reports (periodic reporting of a certain number of strongest pilots, pilot strengths exceeding certain thresholds, pilot strengths order change). Based on the mini-PSMM report, the BS may modify the Active Set for the Supplemental Channel according to the MS's report. The support of MABO is optional for both the MS and the BS. A MABO Supported indicator is included in the MS Capability Information Record. The support of MABO is optional for both the MS and the BS. A MABO Supported indicator is included in the MS Capability Information Record. Benefits MABO allows efficient support of high data rate transmission at a high moving speed through soft handoff (diversity gain with low soft handoff overhead).
67 Mobile Assisted Hard Handoff Enhancements Aligned Candidate Frequency Search was added in IS-2000, where MS can visit the candidate frequency only at predetermined time instances as directed by the BS. In IS-2000-A, “Power Boosting during inter- frequency hard handoff” was introduced to allow increased power on the serving frequency for the transmission of the reminder of a 20ms frame after tuning back from the candidate frequency. Both Aligned Search and Power Boosting for CF Search are optional for the MS and BS. Benefits Increased inter-frequency hard handoff reliability, and therefore lower call drop rate. This feature may also increase the accuracy of the forward and revere link power control during inter-frequency hard handoff.
68 IS-2000 Quality of Service (QoS) End-to-end QoS has not fully been standardized within 3GPP2. Within the air-interface itself, the default service priorities used by the multiplexing sublayer are, in descending order, signaling, primary traffic, secondary traffic. In principle, the MAC multiplexing function should be able to negotiate QoS levels by mediating conflicting requests from competing services and appropriately prioritizing access requests. This behavior still not standardized The QoS parameters within the Access Network (BSs and MS) may include the following: priority, minimum data rate, latency, and data loss data loss for packet data services is defined above RLP, while for circuit data or voice it is simply measured in terms of FER
69 Quality of Service, #2 The following QoS requirements has been included in the air-interface for packet data services: ‘Non-assured’ data services, which are not particularly sensitive to minimum data rate and/or delay and/or data loss. ‘Assured’ data services, which are sensitive to some combination of data rate, delay, and data loss. On the network side, an HLR (Home Location Register) entry has been included for the user specific priority parameter (4-bit value, i.e., 16 priority levels).
70 Power Up Function (PUF) Power Up Function (PUF) allows triangulation techniques be used to locate a MS if several BTS sites can receive the mobile’ signal. Usually in a CDMA system, the mobile transmitter is carefully power controlled to avoid detections by unintended BSs During PUF a MS can quickly increase its transmit power to allow the detection of more than one BSs that may not normally detect this mobile This feature was (and maybe is) mandatory, but it has become obsolete after the publication of IS-801, which define the new and better way of support location information Benefits Allow the BS to calculate the MS location, but could problems due to the large transmit power.
71 CDMA Tiered Services Tiered Service is to provide user custom services and special features based on MS location. It can also provide private network support. To support this feature, IS-2000-A defines the concept of User Zone. A User Zone is a geographic area in which tiered service is available. There are two types of User Zones, broadcast user zones and mobile specific user zones. Broadcast User Zones are notified to the MS using the User Zone Identification Message transmitted on the Paging Channel to allow for subscription. Mobile Specific User Zones are not explicitly identified to the MS using overhead signaling. The MS uses other BS parameters, such as BASE_ID, BASE_LAT, or BASE_LONG, and compares such parameters with an internally stored list of User Zone parameters to identify the user zone.
72 CDMA Tiered Services Requirements The feature is optional for both MS and BS. It will be up to the network operator whether or not to request this feature. One CDMA Tiered service desirable by various operators is the Zone-Based Billing. With zone based billing, the MS in idle state that enters a new “active” zone, as identified by the UZID of the User Zone Identification Message, performs user zone registration. The base responds with a Feature Notification Message that carries the User Zone Update Information record. At this point the MS display informs the user of the billing rates in that zone. Similar procedure can be performed if the MS is already active on the traffic channel. To support such a feature multiple common channel messages must be supported at L3 (messages to support user zone, such as User Zone Identification Message, User Zone Request Message, User Zone Update, and User Zone Reject through Flash With Information Message and/or Feature Notification Message), together with active registration.
73 Enhanced Encryption In Release A, enhanced encryption using the Rijndael algorithm has been introduced This feature is optional for the MS and optional for BS. Benefits Enhanced signaling encryption.
74 Miscellaneous User Feature Enhancements Introduced in IS-2000 but has no relationship to new physical layer of cdma2000. These features are directly visible to the end- user and provide wireline-like services to users. Simply call processing enhancements and therefore is possible to retro-fit into early releases with added software. Advice of Charge: this feature allows Network to deliver usage-based charging information to MS, including start-of-call notification (e.g. rate info), in-call notification (e.g. rate change), and end-of-call notification (e.g. total charge). AOC information record was added. Answer Holding: this feature allows the user to place an incoming call on hold, right when the phone is dialing. The user can then respond to this call at a later convenient time. To support this feature, the MS sends Flash with Information Message with a Feature Indicator Information record during the Waiting for MS Answer substate. The MS may then enter the Conversation Substate after sending the Connect Order.
75 Miscellaneous User Feature Enhancements Enhanced Call Forwarding: This feature allows the user to selectively forward an incoming call to the Voice mail or a number stored in the MS. To effect this, the MS can send Flash with Information Message with a Feature Indicator Information record and possibly, a Called Party Number Information record during Waiting for MS Answer Substate.
76 Rescue Channel To reduce the call drop rate, IS-2000-B introduces the concept of a Rescue Channel, which uses a pre- allocated Walsh code on the neighbor cells to “rescue” a call before it get dropped. The traffic channel maintenance procedure at the MS maintains a fade timer that is reset every time when receiving two good frames. When the fade timer expires (currently set to 5 seconds), the air link is declared as bad and the call is dropped. The procedure relays on the “dropping” mobile to autonomously promote into its active set the neighboring BSs that support a rescue channel. An Extended Pilot Strength Measurement Message (EPSMM) is then sent to let the BS know which pilots in the Active Set were autonomously promoted by the MS itself. If a rescue cell acquires the MS, it will transmit using the pre-allocated Walsh code (RESQ_CODE_CHAN). As soon as the MS receives 2 good frames, the rescue attempt timer is cancelled and the fade timer is reset. At this point, call recovery is completed and the call continues normally. A handoff from the Rescue Channel to a new Traffic Channel can be initiated immediately, to free up call rescue resources.
77 Global Emergency Indicator A new parameter has been added in the Origination Message to support the Global Emergency Indicator in Release A. This feature allows the easy reorganization of any (911 or non-911) type of emergency calls by the network, and better implementation of high priority for these calls with this feature. A special emergency call button may be programmed for special phones or a special designated number may be used to trigger the setting of the parameter for emergency call origination. This feature is optional for the Release A MS and optional for the BS. The development impact of this feature is small Benefits Better support of emergency calls globally
78 Global Emergency Indicator This feature is mandatory for a Release B MS and mandatory for the Release B BS Benefits Reduced call drop rate.
79 Flexible Rate Flexile rate refers to the operation of a Traffic Channel with Radio Configuration 3 or above, where the frame format, including the number of information bits, the number of reserved bits, and the number of frame quality indicator bits, is configurable. Benefits Flexible rate can be useful to support different types of vocoders on a CDMA system, such as GSM vocoders. However, supporting any rate can be less efficient on physical channels that are optimized with fixed set of rates.
80 Variable Rate Supplemental Channel Variable Rate on Supplemental Channel refers to the operational mode of a Forward Supplemental Channel or Reverse Supplemental Channel where the transmitter can change the frame rate among a set of possible choices on a frame-by-frame basis. The “normal” mode of transmission on the supplemental channel is to schedule the rate and duration of a data burst and transmit the entire burst at a fixed rate. This feature is optional for the MS and BS (variable rate can be achieved through FCH). Variable SCH allows more flexible use of SCH.
81 New Repetition Scheme for Flexible and Variable Rate In release A, the flexible and variable data rate transmission chain uses pure code symbol repetition to fill in the enlarged code symbol space, which is defined by the interleaver size for maximum assigned data rate. A low rate turbo coding scheme has been added in Release B for flexible and variable data rate Supplemental Channels. When flexible and variable data rate are supported for Supplemental Channel with turbo codes, low rate turbo codes are used instead of pure code symbol repetition to match the length of encoder output with the interleaver size of maximum assigned data rate. It was claimed that, by doing so, about 1.5dB performance gain can be achievable due to the inherent low rate coding gain. This new scheme is to be used for turbo codes in FL RC 4 and FL RC 5, and RL RC4. This feature is optional for the MS and optional for the BS.
82 Fast Forward Link Power Control Forward Link Inner loop and outer loop: The IS-2000 FFPC utilizes an inner loop and an outer loop, similar to those used for reverse link in IS-95. Inner Loop: compare the received signal to noise ratio to a setpoint. The MS can estimate the FCH/DCCH signal to noise ratio by first measuring the received signal to noise ratio of the power control bits carried on the forward link power control subchannel. Then, knowing the forward link power control subchannel gain relative to the FCH or DCCH, the MS computes the forward FCH/DCCH received signal to noise ratio. Outer Loop: As part of the FFPC the MS also performs an outer loop power control function, which consists in adjusting the signal to noise ratio setpoint in order to achieve the desired FER. The BS controls the target FER and the range of operation of the outer loop via upper layer signaling.
83 FFPC, #2 Not all traffic channels can be fast power controlled. Example: if both FCH and DCCH are active, and the FCH carries the forward link power control subchannel, than the FCH only is power controlled by the reverse link power control subchannel. In such scenario the MS may send the Outer Loop Report Message informing the BS about the difference in setpoint between the FCH and DCCH, so that the BS can adjust the DCCH transmit power properly. This mechanism is necessary considering for example that the DCCH may be operated with a reduced active set or having different FER target from the FCH FER. The Outer Loop Report Message transmission can be triggered either autonomously by the MS, based on BS configured thresholds, or it could be requested by the BS using the Outer Loop Request Message. Summary of Benefits One of the most important features in forward link capacity enhancement for voice users. The required traffic channel received signal to noise ratio for low to medium speed MS is about 2 dB lower than IS-95B. Most of the gain is achieved from pedestrian users.
84 Reduced Active Set & Secondary Power Control Subchannel Reduced Active Set: for high speed data on F-SCH, the soft handoff gain may not compensate for the capacity consumed by the additional link(s) of the SCH active set. Operation of the SCH with a “reduced active set” is often used by the BS., i.e. the F-SCH will use a subset of the FCH or DCCH active set. In such a scenario, the high rate SCH transmit power adjustment based on upper layer signaling alone may not be adequte For example, the sending of the Outer Loop Report Messag, may not be adequate. IS-2000 allows the BS to allocate a secondary power control subchannel on the SCH to control SCH explicitly. In IS-2000 the secondary power control subchannel may be operated at 400 or 600 Hz. Benefits: The secondary power control subchannel allows operating the SCH with a reduced active set, which will reduce capacity consumption especially when the SCH is used for high rate data transmission.
85 Concurrent Services Support more than one services on the same MS device simultaneously Example: simultaneous voice and data. Requires advanced Quality of Service control within both the MS and the BS, alone with more complex call processing. IS-2000 Release A and B allows one simultaneous voice and one data services. One FCH, one DCCH and two SCHs are the maximum configuration allowed. Benefits Better support of multi-media type of services.
86 Diversity Code Combining in Soft Handoff Diversity Code Combining Soft Handoff (CCSH) refers to a new soft handoff scheme using “Iterative Turbo Decoding”, which can achieve some coding diversity gain in addition to the conventional diversity gain during the soft-handoff process. CCSH is a Soft Handoff method where certain BSs encode and transmit the data with the default turbo encoder, whereas others use the complementary turbo encoder. Then the MS combines the code symbols transmitted by each BS for turbo decoding. For a soft handoff involving two BTSs, BTS A to B, for example, first a MS in the area of BTS A is assigned a FL RC 4 supplemental channel using a default turbo encoder with code rate 1/2. As the MS moves into the handoff region of BTS A and BTS B, it starts to combine and decode the signals from BTS A and BTS B.
87 For a conventional soft-handoff method, BTS B shall also use the default turbo encoder so that the resulting code rate at the MS would be 1/2. But, for a CCSH method, BTS B shall use a complementary turbo encoder so that the resulting code rate at the MS would decrease to 1/3. As the MS moves away from the handoff region toward BTS B, BTS B shall continue to use the complementary turbo encoder. This feature is optional for the MS and optional for the BS Benefits Better diversity gain in soft handoff.
88 Call Type Based Access Control Overload Control on the air interface is critical to protect the network as well as to protect the high priority calls such as emergency calls. The overload control mechanism defined before Release B is through the use of Access Overload Class and it cannot distinguish different call types or groups of calls. In Rel B, when overload happens, a network carrier can control the access of a particular type of call, for example, packet data calls or a group of mobiles. Important for wireless networks where both the voice and data services are operated on the same frequency band; when, for example, the packet data network has encountered problems or being upgraded, voice calls can still be allowed to originate while packet calls be blocked. This feature is mandatory for the mandatory for the MS and mandatory for the BS. This feature has some impact on the L2 (and small L3) software but the overall complicity should not be big. This feature is mandatory for the mandatory for the MS and mandatory for the BS. This feature has some impact on the L2 (and small L3) software but the overall complicity should not be big.
89 Reverse Link Power Control Loop Delay IS-2000 allows for an adjustable reverse link power control delay by the BS. In IS-95B a fixed 2-pcg delay is considered valid to puncate/depuncate power control bits. In IS2000 the power control bits can be gated in Control Hold states, and a power control bit is considered valid if it is received in the 1.25ms time slot that starts (REV_PWR_CNTL_DELAYs+1)*1.25ms following the end of a time slot in which the MS transmitter was turned off. The REV_PWR_CNTL_DELAY is setable by BS through ESPM, MC-RR, ECAM, GHDM, UHDM This feature is mandatory for MS and optional for BS. Apply only for RC3 to 6 when the reverse link is gated If MS does not implement reverse pilot gating then no need to support this feature Benefits Better power control during control hold mode.
90 Advanced Packet Data States Control, Active and Dormant State Two most important states characterizing a packet data service Active state: MS allocated dedicated traffic channels for data transmission. Dormant state: both the service configuration information and the RLP state are cleared. Active -> Dormant Transition When no data is available for transmission an inactivity timer is started. The inactivity timer is reset whenever new data becomes available for transmission. Once the inactivity timer expires, the dedicated traffic channels are released and the MS transitions to the dormant state. Dormant -> Active Transition BS pages MS when has data to set, or MS initiates dormant reactivation
91 Advanced Packet Data States Control, Control Hold & Reverse Pilot Gating To transition back from the dormant to the active state, BS has to perform the lengthy procedure of reassigning resources, negotiate the service configuration, and resynchronize RLP the inactivity timer is usually set to a large value to avoid frequent transition A large inactivity timer negatively impact on MS battery life and network capacity since the traffic channel must still carry null frames IS-2000 tries to solve the problem by defining Control Hold state, and by Fast Call Setup procedures (Rel C and above) Control Hold: A MS states where the dedicated traffic channels, FCH or SCH, are released but the BS keeps the DCCH active, and maintains the service configuration information and the RLP state If subsequently service option data becomes available for transmission, the DCCH is used to convey fast signaling (5 ms frames, when supported) with a short turnaround and to re-establish the dedicated traffic channels
92 Advanced Packet Data States Control, Control Hold & Reverse Pilot Gating, #2 Fast Channel re-establishment is possible since MS keeps active the reverse link pilot and power control channels. Optionally, the reverse link pilot channel may be periodically gated off to minimize reverse link capacity consumption in this state, which is usually referred to as the Reverse Pilot Gating.
93 Advanced Packet Data States Control, 1/8 Rate FCH Gating Another feature relevant to advanced MAC state control FCH eighth rate gating feature introduced in IS-2000-A. allows for a FCH to gate off transmission while staying in Active State. This feature is useful when DCCH and Control Hold are not implemented, and FCH is the only physical channel carrying dedicated signaling logical channel. Fast Call Setup: Rel C and D feature to speed up dormant to active transition
94 Advanced Packet Data States Control, Summary of Benefits Control Hold can theoretically help to achieve high network throughput and save MS battery life Allows for very fast traffic channel re-establishment Also allows to set a MAC-level (control hold) inactivity timer to a much smaller value, usually in the order of 100 ms, and therefore to improve air link capacity Not implemented by BS for typical 1x services, may need it for DV FCH eighth rate gating is useful when FCH is the only traffic channel in existence and there is no service option data to send. It can achieve similar nature of benefits as DCCH plus Control Hold.
95 IS-2000 Data Multiplexing IS-95 Multiplex options: 0x01 to 0x10 Frame format: MUX PDU Type 1 & 2 MuxPDU Type 1 for odd-numbered MUX options, and MUX PDU Type 2 for even-numbered MUX options. IS-2000, FCH and DCCH FCH and DCCH can be operated with either MUX option 0x01, using MUX PDU Type 1 or 4, or with MUX option 0x02, using MUX PDU Type 2 or 4. MUX PDU Type 4 are used for the 5 ms frames that carry signaling. The FCH can be operated at variable rate, either Rate Set 1 or Rate Set 2 with MUX options 0x01 and 0x02, respectively. DCCH can be operated at full rate only, either 9.6 or 14.4 kbps, besides DTX
96 IS-2000 Multiplexing IS-2000, SCH SCH at 9.6 or 14.4 kbps reuses the multiplexing function used for the FCH or DCCH: For 9.6 or 14.4 kbps, depending on the fundamental rate used by the corresponding FCH or DCCH, the SCH uses MUX option 0x03 or 0x04, respectively. MUX PDU Type 1 and 2 are used with MUX options 0x03 and 0x04, respectively. IS-2000 MAC multiplexing sublayer also specifies 14 additional MUX options for SCH operated at rates that are multiples of the fundamental rates, i.e., 9.6 kbs for Rate Set 1 and 14.4 kbs for Rate Set 2. Such MUX options are assigned numbers greater than 0x800 and use a frame format defined by MUX PDU Type 3. When using an odd-numbered MUX option corresponding to a data rate greater or equal to 38.4, or when using an even-numbered MUX option corresponding to a data rate greater or equal to 57.6 kbs, the multiplexing sublayer shall assemble the MUX PDU Type 3 in one or more logical transmit units (LTU) to fill the physical layer SDU. The LTU consists of MUX PDU Type 3 followed by a 16-bit CRC.
97 IS-2000 Multiplexing, #2 Up until Release A, the same muxOption is required for FCH and DCCH in the Service Configuration Record. IS-2000 Release B has been enhanced to allow separate multiplex options for FCH and DCCH. allows different rate set and/or Radio Configuration for FCH and DCCH. For examples, RC4 on FCH and RC3 on DCCH. Since multiplex options can be negotiated, the same multiple options can always be used if so desired by either the MS or BS. Benefits Summary Offers flexible options of multiplexing under different conditions.
98 Radio Link Protocol (RLP) Type 3 IS-95 RLP type 1 and 2 cannot efficiently deal with high data rate channels. In particular, the need for segmentation increases the protocol overhead. The retransmission scheme based on RLP frame error rather than RLP segments errors can decrease the system throughput for large RLP frames. RLP type 3 is designed to solve this problem RLP type 3 can support data rate up to 153.6kpbs on a SCH. Uses byte addressing, which means that no segmentation is needed since there are no RLP frame boundaries; RLP3 frames can fit any physical layer frame regardless of its size SEQ field has variable size (21, 13 bits) and an RLP control frame determines its setting. Smaller SEQ field size can be used for lower rates. No reinitializtion is needed when rate is changed. Benefits: More efficient to support high speed data. Because it supports flexible payload frame formats throughput is no longer a multiple of 9.6 kbps No RLP initialization during rate change means less loss of packets.