HSPA systems Kari Aho Senior Research Scientist kari

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HSPA systems Kari Aho Senior Research Scientist kari. aho@magister. fi

HSPA systems Kari Aho Senior Research Scientist kari. aho@magister. fi

Disclaimer § Effort has been put to make these slides as correct as possible,

Disclaimer § Effort has been put to make these slides as correct as possible, however it is still suggested that reader confirms the latest information from official sources like 3 GPP specs (http: //www. 3 gpp. org/Specification-Numbering) § Material represents the views and opinions of the author and not necessarily the views of their employers § Use/reproduction of this material is forbidden without a permission from the author 2 © 2008 Magister Solutions Ltd

Readings related to the subject § General readings § WCDMA for UMTS – H.

Readings related to the subject § General readings § WCDMA for UMTS – H. Holma, A. Toskala § HSDPA/HSUPA for UMTS – H. Holma, A. Toskala § 3 G Evolution - HSPA and LTE for Mobile Broadband - E. Dahlman, S. Parkvall, J. Sköld and P. Beming, § Network planning oriented § Radio Network Planning and Optimisation for UMTS – J. Laiho, A. Wacker, T. Novosad § UMTS Radio Network Planning, Optimization and Qo. S Management For Practical Engineering Tasks – J. Lempiäinen, M. Manninen 3 © 2008 Magister Solutions Ltd

Contents § § § Introduction HSDPA HSUPA Continuous Packet Connectivity I-HSPA Conclusions 4 ©

Contents § § § Introduction HSDPA HSUPA Continuous Packet Connectivity I-HSPA Conclusions 4 © 2008 Magister Solutions Ltd

Introduction 5 © 2008 Magister Solutions Ltd

Introduction 5 © 2008 Magister Solutions Ltd

High Speed Packet Access (1/3) § There were number of pushing forces to improve

High Speed Packet Access (1/3) § There were number of pushing forces to improve the packet data capabilities of WCDMA even further, e. g. § Growing interest towards rich calls, mobile-TV and music streaming in the wireless domain § Competitive technologies such as WIMAX § § § High Speed Packet Access (HSPA) evolution introduced first downlink counterpart of the evolution called High Speed Downlink Packet Access (HSDPA) in Release 5 Uplink evolution followed later in Release 6 by the name of High Speed Uplink Packet Access (HSUPA) HSPA was originally designed for non-real time traffic with high transmission rate requirements 6 © 2008 Magister Solutions Ltd

High Speed Packet Access (2/3) § HSPA features/properties include e. g. § Higher order

High Speed Packet Access (2/3) § HSPA features/properties include e. g. § Higher order modulation and coding § Higher throughput and peak data rates § In theory up to 5, 8 Mbps in the uplink and 14 Mbps in the downlink without Multiple Inputs and Multiple Outputs (MIMO) § Roughly speaking equals to additional transmitter and receiver antennas § Fast scheduling in the Node B § Possibility to take advantage of channel conditions with lower latency 7 © 2008 Magister Solutions Ltd

High Speed Packet Access (3/3) § Link adaptation in downlink § Possibility to adjust

High Speed Packet Access (3/3) § Link adaptation in downlink § Possibility to adjust the used modulation and coding scheme according to be appropriate for current radio channel conditions § Improved retransmission capabilities § Newly introduced layer one retransmissions called as Hybrid Automatic Repeat Request (HARQ) => reduced delay § Radio Link Control (RLC) level retransmissions still possible § Shorter frame sizes and thus Transmission Time Intervals (TTI) § With HSDPA 2 ms and with HSUPA 10 ms and 2 ms 8 © 2008 Magister Solutions Ltd

WCDMA Background and Evolution 3 GPP Rel -99 12/99 2000 Japan 3 GPP Rel

WCDMA Background and Evolution 3 GPP Rel -99 12/99 2000 Japan 3 GPP Rel 4 03/01 2002 Europe (precommercial) 3 GPP Rel 6 (HSUPA) 2 H/04 3 GPP Rel 5 (HSDPA) 03/02 2003 2004 Europe (commercial) 2005 3 GPP Rel 7 HSPA+ 06/07 2006 HSDPA (commercial) Further Releases, (LTE) 2007 HSUPA (commercial) 9 © 2008 Magister Solutions Ltd

Questions § Why were the packet data capabilities of WCDMA improved even further? §

Questions § Why were the packet data capabilities of WCDMA improved even further? § For what kind of services was HSPA originally designed? 10 © 2008 Magister Solutions Ltd

High Speed Downlink Packet Access (HSDPA) 11 © 2008 Magister Solutions Ltd

High Speed Downlink Packet Access (HSDPA) 11 © 2008 Magister Solutions Ltd

Introduction to HSDPA (1/2) § In Release 99 there basically exists three different methods

Introduction to HSDPA (1/2) § In Release 99 there basically exists three different methods for downlink packet data operation § DCH, § Forward Access Channel (FACH) and § Downlink Shared Channel (DSCH) § After the introduction of HSDPA in Release 5 some changes to downlink packet data operations occurred § New High Speed DSCH (HS-DSCH) channel was introduced § DSCH was removed due to lack of interest for implementing it in practical networks 12 © 2008 Magister Solutions Ltd

Introduction to HSDPA (2/2) § HSDPA Improvements for packet data performance both in terms

Introduction to HSDPA (2/2) § HSDPA Improvements for packet data performance both in terms of capacity and practical bit rates are based on § § § The use of link adaptation, Higher order modulation, Fast scheduling, Shorter frame size (or transmission time interval), and Physical layer retransmission § HSDPA does not support DCH features like fast power control or soft handover 13 © 2008 Magister Solutions Ltd

HSDPA channels (1/2) § The Release 99 based DCH is the key part of

HSDPA channels (1/2) § The Release 99 based DCH is the key part of the system – despite the introduction of HSDPA § Release 5 HSDPA is always operated with the DCH § DCH with HSDPA § If the service is only for packet data, then at least the signaling radio bearer (SRB) is carried on the DCH § In case the service is circuit-switched then the service always runs on the DCH § With Release 6, signaling can also be carried without the DCH § In Release 5, uplink user data always go on the DCH (when HSDPA is active) 14 © 2008 Magister Solutions Ltd

HSDPA channels (2/2) § in Release 6 an alternative is provided by the Enhanced

HSDPA channels (2/2) § in Release 6 an alternative is provided by the Enhanced DCH (E-DCH) with the introduction of high-speed uplink packet access (HSUPA) § User data is sent on High Speed Downlink Shared Channel (HS-DSCH) § Control information is sent on High Speed Common Control Channel (HS-SCCH) § HS-SCCH is sent two slot before HS-DSCH to inform the scheduled UE of the transport format of the incoming transmission on HS-DSCH 15 © 2008 Magister Solutions Ltd

Questions § Mention at least purpose to which Rel’ 99 DCH is used with

Questions § Mention at least purpose to which Rel’ 99 DCH is used with HSDPA § What kind of handovers are supported with HSDPA? 16 © 2008 Magister Solutions Ltd

Link Adaptation (1/3) § UE informs the Node B regularly of its channel quality

Link Adaptation (1/3) § UE informs the Node B regularly of its channel quality by CQI messages (Channel Quality Indicator) 17 © 2008 Magister Solutions Ltd

Link Adaptation (2/3) § Adaptive modulation and higher order modulation (16/64 QAM) with HSDPA

Link Adaptation (2/3) § Adaptive modulation and higher order modulation (16/64 QAM) with HSDPA Link adaptation adjusts the mode within few ms based on CQI 18 © 2008 Magister Solutions Ltd

Link Adaptation (3/3) § More complex modulation schemes require more energy per bit to

Link Adaptation (3/3) § More complex modulation schemes require more energy per bit to be transmitted than simply going for transmission with multiple parallel code channels, thus HSUPA benefits more from using multiple codes as PC keeps the signal levels quite good anyway 19 © 2008 Magister Solutions Ltd

Fast Retransmissions (1/3) Rel ‘ 99 HSPA RNC Retransmisson Packet Node. B RLC ACK/NACK

Fast Retransmissions (1/3) Rel ‘ 99 HSPA RNC Retransmisson Packet Node. B RLC ACK/NACK Retransmisson UE § Layer 1 ACK/NACK Radio Link Control (RLC) layer ACK/NACKs also possible with HSPA 20 © 2008 Magister Solutions Ltd

Fast Retransmissions (2/3) UE Node. B RNC User data (Re)transmission RLC (N)ACK MAC-d MAC-hs

Fast Retransmissions (2/3) UE Node. B RNC User data (Re)transmission RLC (N)ACK MAC-d MAC-hs Layer 1 (Re)transmission HARQ (N)ACK 21 © 2008 Magister Solutions Ltd

Fast Retransmissions (3/3) § § § Layer 1 signaling indicates the need of retransmission

Fast Retransmissions (3/3) § § § Layer 1 signaling indicates the need of retransmission which leads to much faster round trip time that with Rel ‘ 99 Retransmission procedure with layer 1 retransmissions (HARQ) is done so that decoder does not get rid of the received symbols if the transmission fails but combines them with new transmissions Retransmissions can operate in two ways: § Identical retransmissions (soft/chase combining) § Non-identical retransmissions (incremental redundancy) 22 © 2008 Magister Solutions Ltd

Questions § § What is CQI? What does link adaptation do? Which entity initiates

Questions § § What is CQI? What does link adaptation do? Which entity initiates RLC re-transmissions? Which entity initiates HARQ re-transmissions? 23 © 2008 Magister Solutions Ltd

Downlink scheduling (1/5) § Node. B has certain amount of users connected to it

Downlink scheduling (1/5) § Node. B has certain amount of users connected to it and it needs to schedule the different users for transmission in different fractions of time (Transmission Time Intervals) § Certain fairness for scheduling time for each user should be maintained § Resources should be utilized in optimal manor § There exists different ways that users can be scheduled in downlink, e. g. § Round Robin § Proportional Fair 24 © 2008 Magister Solutions Ltd

Downlink scheduling (2/5) § Round Robin (RR) § Simplest scheduling algorithms § Assigns users

Downlink scheduling (2/5) § Round Robin (RR) § Simplest scheduling algorithms § Assigns users in order i. e. handling all users without priority § Positive sides § Easy to implement § Each user gets served equally § Negative sides § No channel conditions are taken into account and thus resources might be wasted 25 © 2008 Magister Solutions Ltd

Downlink scheduling (3/5) § Proportional Fair (PF) § Compromise-based scheduling algorithm § Based upon

Downlink scheduling (3/5) § Proportional Fair (PF) § Compromise-based scheduling algorithm § Based upon maintaining a balance between two competing interests § Maximize network throughput i. e. users are served in good channel conditions § Allowing all users at least a minimal level of service 26 © 2008 Magister Solutions Ltd

Downlink scheduling (4/5) § PF assigning each users a scheduling priority that is inversely

Downlink scheduling (4/5) § PF assigning each users a scheduling priority that is inversely proportional to its anticipated resource consumption § High resource consumption => low priority 27 © 2008 Magister Solutions Ltd

Downlink scheduling (5/5) § In general priority metric for certain user can be defined

Downlink scheduling (5/5) § In general priority metric for certain user can be defined as follows § where instantaneous data rate, d, is obtained by consulting the link adaptation algorithm and average throughput, r, of the user is defined and/or updated as follows § where is so called forgetting factor. Hence, equals the equivalent averaging period in a number of TTIs for the exponential smoothing filter 28 © 2008 Magister Solutions Ltd

Mobility with HSDPA (1/4) § Handovers are roughly tradeoff between two issues § When

Mobility with HSDPA (1/4) § Handovers are roughly tradeoff between two issues § When channel conditions are getting worse, handover to better cell should be made so that packets won’t get lost due to poor channel conditions § However, each time when the handover is made, transmission buffers in the Node B are flushed resulting to additional delays from RLC level retransmission or disruption of service § When regarding HSDPA, the user can be connected only to one serving HSDPA Node B at the time § Leading to hard handover when the handover between HSDPA Node Bs is required in contrary to DCH soft handover 29 © 2008 Magister Solutions Ltd

Mobility with HSDPA (2/4) § Even though there is only one serving HS-DSCH cell,

Mobility with HSDPA (2/4) § Even though there is only one serving HS-DSCH cell, the associated DCH itself can be in soft(er) handover and maintain the active set as in Rel’ 99 Node B, Serving HSDPA DCH HS-SCCH DCH/HSDPA Node B, Part of DCH active set UE DCH 30 © 2008 Magister Solutions Ltd

Mobility with HSDPA (3/4) § HSDPA handover procedure includes following steps § Serving HS-DSCH

Mobility with HSDPA (3/4) § HSDPA handover procedure includes following steps § Serving HS-DSCH cell change procedure is initiated when a link in (DCH) active set becomes higher in strength and stays stronger for certain period of time, referred as time-to-trigger § If the condition mentioned above is met then the measurement report is sent from the UE to the Node B, which forwards it to the RNC § If e. g. the admission control requirements are met the RNC can then give the consent for the UE to make the handover by sending so called Signaling Radio Bearer (SRB) (re)configuration message 31 © 2008 Magister Solutions Ltd

Mobility with HSDPA (4/4) § In the case of intra Node B handover, the

Mobility with HSDPA (4/4) § In the case of intra Node B handover, the HARQ processes (transmissions) and Node B buffers can be maintained and thus there is only minimal interruption in data flow § However, with inter Node B handover i. e. between Node Bs, the Node B packet buffers are flushed including all unfinished HARQ processes which are belonging to the UE that is handed off 32 © 2008 Magister Solutions Ltd

Questions § How does Round Robin allocate resources for the users? § How intra-

Questions § How does Round Robin allocate resources for the users? § How intra- and inter-Node B handovers differ from each other? 33 © 2008 Magister Solutions Ltd

High Speed Uplink Packet Access (HSUPA) 34 © 2008 Magister Solutions Ltd

High Speed Uplink Packet Access (HSUPA) 34 © 2008 Magister Solutions Ltd

Introduction to HSUPA (1/2) § Roughly three years later when HSDPA was introduced uplink

Introduction to HSUPA (1/2) § Roughly three years later when HSDPA was introduced uplink counterpart of the high speed packet access evolution was introduced in Release 6 § In 3 GPP original name was not HSUPA but Enhanced Dedicated Channel (E-DCH) § The obvious choices for uplink evolution was to investigate the techniques used for HSDPA and, if possible, adopt them for the uplink as well § Improvements in HSUPA when compared to Rel’ 99 § Layer 1 Hybrid ARQ (HARQ) i. e. fast retransmissions § Node B based scheduling 35 © 2008 Magister Solutions Ltd

Introduction to HSUPA (2/2) § Easier multicode transmissions § Shorter frame size, 10 ms

Introduction to HSUPA (2/2) § Easier multicode transmissions § Shorter frame size, 10 ms mandatory for all HSUPA capable devices and 2 ms as optional feature § HSUPA is not a standalone feature, but requires many of the basic features of the WCDMA Rel’ 99 § § Cell selection and synchronization, random access, basic power control loop functions, basic mobility procedures (soft handover), etc. 36 © 2008 Magister Solutions Ltd

HSUPA channels (1/4) § New uplink transport channel - Enhanced Dedicated Channel (E-DCH) §

HSUPA channels (1/4) § New uplink transport channel - Enhanced Dedicated Channel (E-DCH) § Supports key HSUPA features such as HARQ, fast scheduling etc. § Unlike HS-DSCH (HSDPA) E-DCH is not a shared channel, but a dedicated channel (*) § Similarly to DCH, E-DCH is also mapped to physical control and data channels § The user data is carried on the enhanced dedicated physical data channel (E-DPDCH) while new control information is on the EDPCCH (*)Dedicated channel means that each UE has its own data path to the Node B that is continuous and independent from the DCHs and E-DCHs of other UEs 37 © 2008 Magister Solutions Ltd

HSUPA channels (2/4) § From the Release 99 DCH, the dedicated physical control channel

HSUPA channels (2/4) § From the Release 99 DCH, the dedicated physical control channel (DPCCH) is unchanged and the need for the DPDCH depends on possible uplink services mapped to the DCH § DPCCH is used e. g. for fast power control § New channels for scheduling control § E-DCH absolute grant channel (E-AGCH) - absolute scheduling value § E-DCH relative grant channel (E-RGCH) - relative step up/down scheduling commands 38 © 2008 Magister Solutions Ltd

HSUPA channels (3/4) § New channel for retransmission control, carries information in the downlink

HSUPA channels (3/4) § New channel for retransmission control, carries information in the downlink direction on whether a particular base station has received the uplink packet correctly or not § E-DCH HARQ indicator channel (E-HICH) 39 © 2008 Magister Solutions Ltd

HSUPA channels (4/4) DPCCH Node. B E-DPCCH E-DPDCH E-RGGH UE E-AGCH E-HICH 40 ©

HSUPA channels (4/4) DPCCH Node. B E-DPCCH E-DPDCH E-RGGH UE E-AGCH E-HICH 40 © 2008 Magister Solutions Ltd

Questions § What new features on top of multicodes and shorter frame sizes do

Questions § What new features on top of multicodes and shorter frame sizes do HSUPA offer? § Is DCH part of the HSUPA? 41 © 2008 Magister Solutions Ltd

Uplink scheduling (1/5) § With HSDPA all the cell power can be directed to

Uplink scheduling (1/5) § With HSDPA all the cell power can be directed to a single user for a short period of time § Very high peak data rates achievable for certain UE and all the others can be left with a zero data rate § However, in the next time instant another UE can be served and so on § With HSUPA HSDPA type of scheduling is not possible § HSUPA is a many-to-one scheduling § The uplink transmission power resources are divided to separate devices (UEs) which can be used only for their purposes and not shared as with HSDPA 42 © 2008 Magister Solutions Ltd

Uplink scheduling (2/5) § The shared resource of the uplink is the uplink noise

Uplink scheduling (2/5) § The shared resource of the uplink is the uplink noise rise(*), or the total received power seen in the Node B receiver § Typically, one UE is unable to consume that resource alone completely and it is very beneficial for the scheduler to know at each time instant how much of that resource each UE will consume and to try to maintain the interference level experienced close to the maximum § Thus, HSUPA scheduling could be referred as very fast DCH scheduling (*)ratio between the total power received from all of the UEs at the base station and thermal noise 43 © 2008 Magister Solutions Ltd

Uplink scheduling (3/5) § Two different scheduling schemes are defined for HSUPA traffic §

Uplink scheduling (3/5) § Two different scheduling schemes are defined for HSUPA traffic § Scheduled transmissions controlled by Node B which might not guarantee high enough minimum bit rate. In addition each request requires time consuming signaling § Non-scheduled transmissions (NST) controlled by radio network controller (RNC) which defines a minimum data rate at which the UE can transmit without any previous request. This reduces signaling overhead and consequently processing delays 44 © 2008 Magister Solutions Ltd

Uplink scheduling (4/5) § Scheduled transmissions § The scheduler measures the noise level and

Uplink scheduling (4/5) § Scheduled transmissions § The scheduler measures the noise level and decides whether § Additional traffic can be allocated § Should some users have smaller data rates § The scheduler also monitors the uplink feedback § Transmitted on E-DPCCH in every TTI § Referred as happy bits § Tells which users could transmit at a higher data rate both from the buffer status and the transmission power availability point of view 45 © 2008 Magister Solutions Ltd

Uplink scheduling (5/5) § Depending on possible user priorities given from the RNC, the

Uplink scheduling (5/5) § Depending on possible user priorities given from the RNC, the scheduler chooses a particular user or users for data rate adjustment § The respective relative or absolute rate commands are then send on the E-RGCH or E-AGCH § UE in soft handover receives only relative hold/down commands from other than serving HSUPA Node B 46 © 2008 Magister Solutions Ltd

Questions § What is the shared resource in the uplink if power is in

Questions § What is the shared resource in the uplink if power is in the downlink? § What kind of scheduling possibilities HSUPA offer? 47 © 2008 Magister Solutions Ltd

Multicodes with HSUPA (1/2) § Even though Rel’ 99 DCH supports in theory multicode

Multicodes with HSUPA (1/2) § Even though Rel’ 99 DCH supports in theory multicode transmissions in practice only E-DCH can support multicode transmissions and thus higher bitrates § In theory DCH can use 6 x. SF 4 leading to 5. 4 Mbps § E-DCH can in practice support 2 x. SF 2 + 2 x. SF 4 leading to 5. 4 Mbps § The reason why DCH does not support multicodes is that the DCH is controlled by RNC and thus DCH is rather slowly controllable 48 © 2008 Magister Solutions Ltd

Multicodes with HSUPA (2/2) § If the UE could send with fully utilizing multicodes

Multicodes with HSUPA (2/2) § If the UE could send with fully utilizing multicodes in some time instant this might not be the case later and UE might end up in power outage and thus wouldn’t be able to use its allocation § With RNC control reallocation of resources is slow => resources wasted § Also, HSUPA with HARQ increases the possibility to operate with higher BLER target which leads to lower power requirement for corresponding data rate 49 © 2008 Magister Solutions Ltd

Mobility with HSUPA (1/2) § HSUPA supports the soft(er) handover procedure similar to WCDMA

Mobility with HSUPA (1/2) § HSUPA supports the soft(er) handover procedure similar to WCDMA Rel’ 99 § The HARQ operation in HSUPA soft handover situation is done in following manor § If any Node B part of the active set sends an ACK, then the information given to the Medium Access Control (MAC) layer is that an ACK has been received and the MAC layer will consider the transmission successful 50 © 2008 Magister Solutions Ltd

Mobility with HSUPA (2/2) Packet reordering RNC Correctly received packet Node. B Layer 1

Mobility with HSUPA (2/2) Packet reordering RNC Correctly received packet Node. B Layer 1 ACK/NACK Data Node. B UE Layer 1 ACK/NACK 51 © 2008 Magister Solutions Ltd

Questions § Why does not DCH support multicodes in practice? § If UE is

Questions § Why does not DCH support multicodes in practice? § If UE is in a two-way soft handover how does the HARQ operate? 52 © 2008 Magister Solutions Ltd

Continuous Packet Connectivity (CPC) 53 © 2008 Magister Solutions Ltd

Continuous Packet Connectivity (CPC) 53 © 2008 Magister Solutions Ltd

Continuous Packet Connectivity (1/5) § Continuous Packet Connectivity (CPC) was released in Release 7

Continuous Packet Connectivity (1/5) § Continuous Packet Connectivity (CPC) was released in Release 7 § Designed to improve the performance of delay critical small bit rate services like Vo. IP § Eliminates the need for continuous transmission and reception when data is not exchanged. Can be categorized into three feature § UL discontinuous transmission § DL discontinuous transmission § HS-SCCH less for HSDPA Vo. IP 54 © 2008 Magister Solutions Ltd

Continuous Packet Connectivity (2/5) § Benefits § Connected inactive HSPA users need less resources

Continuous Packet Connectivity (2/5) § Benefits § Connected inactive HSPA users need less resources and create less interference => more users can be connected § UE power savings => increased talk time (Vo. IP) § UTRAN resources are saved 55 © 2008 Magister Solutions Ltd

Continuous Packet Connectivity (3/5) R 99 DCH with 20 -ms TTI (Rel’ 99, CS

Continuous Packet Connectivity (3/5) R 99 DCH with 20 -ms TTI (Rel’ 99, CS voice) E-DCH with 10 -ms TTI (Rel’ 6, phase 1, Vo. IP) 12. 2 kbps DCH 32 kbps E-DCH 160 kbps E-DCH Power offset E-DCH with 2 -ms TTI (Rel-6, phase 2, Vo. IP) 160 kbps E-DCH with 2 ms TTI and UL DPCCH gating (Rel-7, Vo. IP) PO = DPDCH (DCH) / E-DPDCH (E-DCH) = DPCCH 56 © 2008 Magister Solutions Ltd

Continuous Packet Connectivity (4/5) § DL discontinuous transmission or Discontinuous Reception (DRx) cycles allow

Continuous Packet Connectivity (4/5) § DL discontinuous transmission or Discontinuous Reception (DRx) cycles allow an idle UE to power off the radio receiver for a predefined period § Period after the UE wakes up again is called as DRx cycle § When UE wakes up it listens predefined time for incoming transmissions and if it successfully decodes a new transmission during that time it starts timer for staying active certain period of time No measurements done or data received 57 © 2008 Magister Solutions Ltd

Continuous Packet Connectivity (5/5) § HS-SCCH-less HSDPA operation in downlink § Initial transmission of

Continuous Packet Connectivity (5/5) § HS-SCCH-less HSDPA operation in downlink § Initial transmission of small (Vo. IP) packets can be sent without High Speed Secondary Control Channel (HS-SCCH) § Eliminates the control channel overhead from small packets sent over HSDPA § Retransmissions are sent with HS-SCCH pointing to the initial transmission 58 © 2008 Magister Solutions Ltd

Vo. IP performance with and without CPC § In general major performance enhancements visible

Vo. IP performance with and without CPC § In general major performance enhancements visible if circuit switched voice over WCDMA and Vo. IP over HSPA Rel 7 is compared § § With Rel 99 CS voice capacity 60 -70 users/cell With Rel 7 Vo. IP capacity goes beyond 120 users/cell H. Holma, M. Kuusela, E. Malkamäki, K. Ranta-aho, C. Tao: “Vo. IP over HSPA with 3 GPP Release 7”, PIMRC, 2006. 59 © 2008 Magister Solutions Ltd

Internet HSPA (I-HSPA) 60 © 2008 Magister Solutions Ltd

Internet HSPA (I-HSPA) 60 © 2008 Magister Solutions Ltd

I-HSPA (1/3) § Internet-HSPA (I-HSPA) aims to provide competitive mobile internet access with much

I-HSPA (1/3) § Internet-HSPA (I-HSPA) aims to provide competitive mobile internet access with much more simpler network architecture than it is in normal WCDMA systems § Deployable with existing WCDMA base stations § Utilizes standard 3 GPP terminals § Simplified architecture brings many benefits such as § § § Cost-efficient broadband wireless access Improves the delay performance Transmission savings Enables flat rating for the end user Works anywhere (compared to WLAN or WIMAX) 61 © 2008 Magister Solutions Ltd

I-HSPA (2/3) Node. B / E-Node. B UE SGSN RNC GGSN Internet / Intranet

I-HSPA (2/3) Node. B / E-Node. B UE SGSN RNC GGSN Internet / Intranet I-HSPA 62 © 2008 Magister Solutions Ltd

I-HSPA (3/3) Release 99 ~200 ms Round trip time of 32 -Byte packet 200

I-HSPA (3/3) Release 99 ~200 ms Round trip time of 32 -Byte packet 200 HSDPA <100 ms 180 160 Internet Iu + core RNC Iub Node B AI UE HSUPA ~50 ms 140 120 100 I-HSPA ~25 ms 80 60 40 20 0 Today HSDPA+HSUPA I-HSDPA+ I-HSUPA 63 © 2008 Magister Solutions Ltd

Conclusions 64 © 2008 Magister Solutions Ltd

Conclusions 64 © 2008 Magister Solutions Ltd

Conclusions (1/2) § High Speed Packet Access evolution for WCDMA was introduced in Release

Conclusions (1/2) § High Speed Packet Access evolution for WCDMA was introduced in Release 5 and 6 for downlink and uplink, respectively § HSPA offers much higher peak data rates, reaching in theory up to 14 Mbps in the downlink and 5, 4 Mbps in the uplink, in addition to reduced delays § Key technologies with HSPA are Fast Layer 1 retransmissions i. e. HARQ Node B scheduling Shorter frame size (2 ms in DL and 2/10 ms UL) Higher order modulation and coding along with link adaptation in downlink § Real support for multicodes in the uplink § § 65 © 2008 Magister Solutions Ltd

Conclusions (2/2) § HSPA improved also the performance of delay critical low bit rate

Conclusions (2/2) § HSPA improved also the performance of delay critical low bit rate services like Vo. IP even though it was not originally designed for it § Continuous Packet Connectivity (CPC) enhancements introduced in Release 7 improved Vo. IP performance even more § I-HSPA was introduced to provide competitive internet access solution § High data rates with low delay § Reduced costs => flat rate could be possible § Femtocells were introduced to improve the mobile convergence and performance in small offices or at home, for instance 66 © 2008 Magister Solutions Ltd

HSPA vs DCH (basic WCDMA) Feature DCH HSUPA HSDPA Variable spreading factor Yes No

HSPA vs DCH (basic WCDMA) Feature DCH HSUPA HSDPA Variable spreading factor Yes No Multicode transmission Yes Yes Fast power control Yes No Soft handover Yes No Adaptive modulation No No Yes BTS based scheduling No Yes Fast L 1 HARQ No Yes (No in practice) (associated DCH only) 67 © 2008 Magister Solutions Ltd

HSPA Peak Data Rates Downlink HSDPA § Theoretical up to 14. 4 Mbps §

HSPA Peak Data Rates Downlink HSDPA § Theoretical up to 14. 4 Mbps § Initial capability 1. 8 – 3. 6 Mbps # of codes Modulation Uplink HSUPA § Theoretical up to 5. 76 Mbps § Initial capability 1. 46 Mbps Max data rate # of codes TTI Max data rate 5 codes QPSK 1. 8 Mbps 2 x SF 4 2 ms 10 ms 1. 46 Mbps 5 codes 16 -QAM 3. 6 Mbps 2 x SF 2 10 ms 2. 0 Mbps 10 codes 16 -QAM 7. 2 Mbps 2 x SF 2 2 ms 2. 9 Mbps 15 codes 16 -QAM 10. 1 Mbps 2 x SF 2 + 2 x SF 4 2 ms 5. 76 Mbps 15 codes 16 -QAM 14. 4 Mbps 68 © 2008 Magister Solutions Ltd

Thank you! kari. aho@magister. fi 69 © 2008 Magister Solutions Ltd

Thank you! kari. aho@magister. fi 69 © 2008 Magister Solutions Ltd