8. 3 GPPP technologies and services

1. 8. 3 GPPP technologies and services 8.1. High Speed Downlink Packet Access (HSDPA) 8.2. IMS services

2. 8.1. High Speed Downlink Packet Access (HSDPA) 3 GPPP Rel’5 of UMTS was completed in March 2002. Rel’5 introduces the IP Multimedia System (IMS) architecture that promises to greatly enhance the end-user experience for Integrated multimedia applications and offer the mobile operator an efficient means for offering such services. 3 GPPP Rel’5 will provide higher speed wireless data services with vastly improved spectral efficiencies through the High Speed Downlink Packet Access (HSDPA) feature.

3. Release 5 (Rel’5) of the 3GPP (Cntd.) High Speed Downlink Packet Access (HSDPA) offers significantly higher data capacity and data user speeds on the downlink (theoretically up to 14 Mbps peak) compared to R’99 UMTS through the use of very dynamic adaptive modulation, coding and scheduling with Hybrid Automatic Retransmission Request (H-ARQ) processing. Through HSDPA, operators will benefit from a technology that will provide improved end-user experience for Web access, file download and streaming Services,Wireless Broadband access to the Internet, intranet and corporate LAN will benefit greatly from HSDPA.

4. High Speed Downlink Packet Access (HSDPA) HSDPA is based on a new distributed architecture enabling: • low delay link adaptation, • channel quality feedback • H-ARQ processing. This is accomplished by incorporating many of the key scheduling and control processes at the base station, as opposed to the Radio Network Controller RNC, and thus closer to the air-interface. Specifically , the Medium Access Control (MAC) functionality, which fully resided in the RNC in R’99, is split between the RNC and Node B (i.e. the base station) in Rel’5. Main mechanisms of HSDPA are: • dynamic adaptive modulation and coding, • multi-code operation, • fast scheduling • physical layer retransmissions.

5. HSDPA system architecture

6. HSDPA main mechanisms High-Speed Downlink Shared CHannel (HS-DSCH) HSDPA defines a new transport channel type, known as the High-Speed Downlink Shared CHannel (HSDSCH), which allows several users to share the air interface channel dynamically with peak channel rates up to 14 Mbps. The HS -DSCH supports QPSK and 16-QAM modulations , link adaptation, and the retransmission at the physical layer with H-ARQ. Fast scheduling In HSDPA it realizes on the base station, and thus closer to the air interface. HSDPA uses terminal feedback information about channel quality, terminal capabilities, quality of service (QoS) needs, and air interface resource availability to achieve more efficient scheduling of data packet transmissions. HSDPA can, for example, manage scheduling to track fast fading fluctuations of the users and allocate resources to a single user (or a few number of users) for very short periods of time when their channel conditions are favorable. The Proportional Fairscheduler is one example of a scheduler that prioritizes users in the best channel conditions. Round-robin scheduler is anothr example of a scheduler.

7. HSDPA main mechanisms (Cntd.) Channel Quality Feedback To accommodate fast Channel Quality Indications (CQI) and ACK/NACK signaling for H- ARQ from the terminal, an uplink High-Speed Dedicated Physical Control CHannel (HS-DPCCH) is defined. The base station gathers and utilizes the CQI of each active user to determine when each user is scheduled on the HS-DSCH. Adaptive modulation and coding The fast scheduling capability of HSDPA can be taken advantage of through adaptive modulation and coding to provide all users the highest possible data rate. The modulation and coding schemes are adapted dynamically based on the quality of the radio link while maintaining the power level constant. In addition to QPSK, HSDPA defines 16-QAM modulation that can be used when interference conditions are favorable. Rate 1/3 turbo coding is used in HSDPA. However, by varying the transport block size, modulation and number of multi-codes the effective code rate can be anywhere from ¼ to ¾. Through H-ARQ the code rate can approach 1.

8. Capacity Improvement of HSDPA

9. Capacity Improvement of HSDPA The PF scheduler improves the aggregate throughput by prioritizing users in good channel conditions while still maintaining a minimum throughput performance level for users in poor channel conditions. Results for HSDPA with advanced receivers in the terminal including 2-way receive diversity (two antennas and equalization in the terminal are also shown. Figure illustrates that HSDPA offers more than a three times increase in data capacity (without advanced receivers in the terminals) for densely populated environments (i.e. micro cell) where capacity demands are typically the greatest. With advanced terminals, HSDPA can offer nearly five times the data capacity of R’99 UMTS.

10. 8.2. IMS services PaT - new IMS-based service in wireless networks

11. PaT - new IMS-based service in wireless networks (Cntd.)

12. PaT Operation First, the user selects the people he or she wants to talk to from a list. At the push of a button, all of these previously defined addressees immediately receive an invitation, which they can accept or decline. As soon as the participants have confirmed, the initial caller pushes the PaT button and starts the chat, which everyone hears simultaneously. There is no time-consuming call setup, because the “Always On” feature of the GPRS network maintains the connection all along. Any group member can reply immediately by pressing the PaT button. The communication can only go in one direction at a time, however, whoever presses the PaT button first, talks first. PaT service has been successful in the U.S., where according to a study by Zelos, market research company, PaT ranges in second place among desirable mobile phone features, directly after a color display.

13. Presence In computing, is defined as the "availability and willingness of the user for communication". Presence information is published by individuals to other systems users, known as 'watchers' or 'subscribers', to indicate their communication state. Although not limited to IP communications, it has become synonymous with IP applications such as VoIP and Instant Messaging. A user may publish a variety of presence states to indicate their communication status. This published state informs others that wish to contact the user of their availability and willingness to communicate. The most common use of presence today is the status indicator displayed on most instant messaging clients. Some example presence states are: • Free for Chat • Away • Do not Disturb ………

14. Presence (Cntd.) The presence service enabler allows a set of users to be informed about the availability and means of communication of the other users in the group. It enables a paradigm shift in person-to-person and other communications – for example, by enabling users to ‘see’ each other before connecting (active address book) or to receive alerts when other users become available. In IMS, presenceis sensitive to different media types, users (requestors), and user preferences. IMS presence function is also aware of what terminals the user can be reached on across the various wireline and wireless networks. Different rules can be set by the user to define who can view what information.

15. Group list management The group list managementservice enabler allows users to create and manage network-based group definitions for use by any service deployed in the network. There are generic mechanisms for notification of changes in group definitions. Application examples for group management include: personal buddy lists • ‘block’ lists • public/private groups (for example, the easy • definition of VPN-oriented service packages) • access control lists • public or private chat groups • any application where a list of public identities is required. New multimedia capabilities will be added over time – including video, messaging, personalized push services, etc. in order to further enhance the packet switched service offering.

16. Instant messaging • Instant messaging (sometimes called IM or IMing) is the ability to easily see whether a chosen friend or co-worker is connected to the Internet and, if they are, to exchange messages with them. Instant messaging differs from ordinary e-mail in the immediacy of the message exchange and also makes a continued exchange simpler than sending e-mail back and forth. Most exchanges are text-only. However, some services, such as AOL, allow voice messaging and file sharing.

17. Instant messaging (Cntd.) • In order for IM to work, both users (who must subscribe to the service) must be online at the same time, and the intended recipient must be willing to accept instant messages. (It is possible to set your software to reject messages.) An attempt to send an IM to someone who is not online, or who is not willing to accept IMs, will result in notification that the transmission cannot be completed. If the online software is set to accept IMs, it alerts the recipient with a distinctive sound, a window that indicates that an IM has arrived and allowing the recipient to accept or reject it, or a window containing the incoming message.

18. Mapping of Wireless Data Services to Preferred Speeds

19. Instant messaging (Cntd.) • Under most conditions, IM is truly "instant." Even during peak Internet usage periods, the delay is rarely more than a second or two. It is possible for two people to have a real-time online "conversation" by IMing each other back and forth. • Once in a while, a person might receive an IM from someone while already engaged in a chat with someone else, and decide to carry on IM chats with both people independently and concurrently. This requires mental alertness to avoid the embarrassment of sending one IM companion a message intended for the other.

20. Service evolution