Über die Autorin bzw. den Autor

Pablo Tapia is a Principal Engineer at T-Mobile, US. He delivers consultancy services to T-Mobile USA within the Network Evolution and Strategy Group at T-Mobile Headquarters, working closely with Nokia and Ericsson. Before moving to the US he was Lead Consultant at Optimi in Spain, where he supplied T-Mobile International (15+ operators) with a corporate solution for WCDMA Optimization, including RF planning and optimization. Previous to this he set up Nokia Networks R&D center in China. He has a multidisciplinary background, including experience in R&D in network vendors, software development and operator experience, with contribution to multiple papers, and co-designer of several patents. He is a contributor to two Wiley books.

Jun Liu is also a Principal Engineer at T-Mobile, US. He has co-authored a number of papers with Pablo Tapia.

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Written from an operator’s viewpoint, HSPA Performance and Evolution explores the lessons learned and techniques developed for optimally deploying HSPA (High Speed Packet Access). The essential distinctions between rolling out HSPA compared to earlier UMTS and GSM technologies are explained covering the many issues that must be specifically handled. Areas in standards which have been left open for interpretation, causing significant differences between vendor implementations, are identified and solutions explored.

This book is invaluable in enabling wireless operators to extract maximum performance offered by 3GPP’s HSPA radio technology, consisting of both downlink (HSDPA) and uplink (HSUPA) elements. It focuses on real-world performance, sharing practical implementation methods and tradeoffs for deploying, optimizing and maintaining networks using the HSPA air interface.

• Examines algorithms, equipment and performance perspectives to identify and explain HSPA

• Measures performance and sets network parameters for optimal tradeoffs

• Presents results from practical and real-world network performances

• Explores the evolution of HSPA technology into HSPA+ and eventually next generation LTE technologies

Aus dem Klappentext

Written from an operator’s viewpoint,  HSPA Performance and Evolution  explores the lessons learned and techniques developed for optimally deploying HSPA (High Speed Packet Access). The essential distinctions between rolling out HSPA compared to earlier UMTS and GSM technologies are explained covering the many issues that must be specifically handled. Areas in standards which have been left open for interpretation, causing significant differences between vendor implementations, are identified and solutions explored.

This book is invaluable in enabling wireless operators to extract maximum performance offered by 3GPP’s HSPA radio technology, consisting of both downlink (HSDPA) and uplink (HSUPA) elements. It focuses on real-world performance, sharing practical implementation methods and tradeoffs for deploying, optimizing and maintaining networks using the HSPA air interface.

 • Examines algorithms, equipment and performance perspectives to identify and explain HSPA

• Measures performance and sets network parameters for optimal tradeoffs

• Presents results from practical and real-world network performances

• Explores the evolution of HSPA technology into HSPA+ and eventually next generation LTE technologies

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HSPA Performance and Evolution

John Wiley & Sons

Chapter One

There are fundamental shifts in philosophy and strategy taking place as the wireless industry matures and the power of the internet converges with the world of mobility. That appeal has drawn important new players into wireless with familiar names like Apple, Google, eBay/ Skype, Yahoo!, Microsoft, Disney, CNN and ESPN. The success and innovation of social networking sites such as Facebook and MySpace have triggered numerous companies to transport these ideas to the mobile realm. The underpinning for most of these emerging areas is the widespread availability of broadband wireless accessprecisely the capability that High Speed Packet Access (HSPA) promises to deliver.

The wireless industry has reached a true crossroads with packet data services beginning to overtake traditional circuit-switched voice services. Broadband wireless access technologies such as HSPA can bring wired internet performance to the mobile domain. The combination of high data rates, low latencies and mobility enables a new generation of wireless applications not possible or even conceivable with prior technologies. In these emerging broadband wireless systems, voice itself is transported over the packet data interfaces. There are many intermediate steps involved as wireless networks transition from current circuit- to future packet-switched architectures, with HSPA and HSPA+ being two of the critical ones. Mobile service providers must efficiently master these technologies to take full advantage of broadband wireless capabilities.

With this convergence of the internet and wireless industries, the landscape has become dramatically more competitive. Broadband wireless performance is now a serious competitive differentiator in the marketplace. Customer expectations have also markedly risen, with a new generation of consumers expecting wireless systems to deliver mobile performance on par with their fixed-line DSL or cable modem home systems. To step up to that competitive challenge, wireless operators must deploy, optimize and maintain broadband wireless networks achieving dramatically higher data rates and lower latencies. This task involves not just selecting the right air interface, but also having the best possible techniques and tools to elicit optimal performance, while balancing the inevitable network quality, coverage and capacity tradeoffs.

In this book we concentrate on extracting the most from the capabilities offered by 3GPP's HSPA radio technology, consisting of both downlink (HSDPA) and uplink (HSUPA) elements. With data rates on the downlink up to a whopping 8-10 Mbps and latencies of less than 100 milliseconds, HSPA promises to deliver the full wired internet experience to the wireless world. The big data pipe comes courtesy of extremely short time slots, fast channel quality feedback and speedy retransmissions. HSPA enables dramatically faster download times and snappier connections compared to its predecessors EDGE and GPRS, called (E)GPRS, which is great for all applications but especially demanding services like video apps. Ironically in the longer term, the real benefit may lie in the voice domain - namely high-capacity and low-latency wireless Voice over IP (VoIP) services. With technical tricks such as header compression and fast dynamic power sharing, voice could be another data offering while increasing the overall network capacity compared to today's circuit-switched networks.

The wireless industry is currently observing a whirlwind of activity to invent the next big technology. The main standards groups, 3GPP, 3GPP2 and IEEE, are all hard at work on future technologies to get 4G to market - in the form of Long Term Evolution (LTE), and Mobile WiMAX. While many players in the industry are putting efforts into developing future technologies beyond 3G, we believe that the HSPA investment provides a strong and flexible platform for operators to offer highly competitive products for many years to come. In the next few years, Mobile WiMAX will enter the market as a wide area network for offering broadband wireless. From customers' perspectives both HSPA and Mobile WiMAX offer similarly high data rates and low latencies. The key advantages for HSPA are its technical maturity (being based on UMTS) and ubiquitous availability from many operators around the globe and in many devices. What many people do not realize is that for the foreseeable future, the competition for WiMAX is HSPA. Much later, when LTE enters the market in 2010+ it will likely compete with an evolved Mobile WiMAX, but it will take a number of years for LTE to reach mass scale in terms of footprint and devices. Without a doubt, HSPA will be the flag-bearer for broadband wireless services in the 3GPP world for many years to come. The aim of this book is to share practical implementation methods and tradeoffs for deploying, optimizing and maintaining networks using the HSPA air interface. The imperative word is `practical', as opposed to standards, research and theory. That means we focus on real-world performance in operator's networks. We will not dive too deeply into simulation results, and we will not present theoretical derivations that you might read in research papers or in many other books written by research and development teams. Instead we will focus on lessons learned from, and techniques for optimally deploying HSPA in the field from an operator's viewpoint. We identify areas where standards have left items open for interpretation, which causes significant differences between vendor implementations. We will do so without divulging vendor proprietary algorithms, but in a way that explains what operators can expect. We also explain the essential distinctions between rolling out HSPA compared to earlier UMTS and GSM technology, because there are many issues that must be handled differently.

1.1 Services and Applications for HSPA

Before diving into the technology of HSPA itself, it's worthwhile examining first the evolving data services, applications and the related ecosystem. As noted, the search is still on for a killer application for wireless data - the proverbial `Holy Grail' that will make wireless data services as necessary to the user as the current voice service. Meanwhile, mobile operators around the world are experiencing steady increases in their networks' data usage and more importantly the associated revenues, driven by the launches of new network technologies and the availability of advanced Smartphone and Personal Digital Assistant (PDA) devices. This trend can clearly be seen from the growth in Figure 1.1, which shows trends in both total data revenues and the percentage of data revenues out of Average Revenue per User (ARPU).

More than relying on a single killer application, a wider adoption of data services is instead dependent on other factors, including the handset usability (user interface, processing power and speed), the capabilities of the network technology (e.g. throughput and latency), the price of the data plans, and the operators' openness to accepting new applications and partners. HSPA can certainly plan an important role in driving this adoption.

When introducing a new air interface technology, we have found that the laggard has typically been the handset capabilities rather than the network. The reasons for this have been the severe...