1. © 2008 AT&T Intellectual Property. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Intellectual Property. The Path to 4G April 2, 2008 Kris Rinne

2. April 14, 2015 Page 2 Growth Drivers: Wireless Data Apps Percentage of U.S. cell phone subscribers who used their phones for various activities beyond merely making phone calls. Survey of U.S. Mobile subscribers; Data based on three-month average for period ending July 31, 2007. Source: M:Metrics Inc.

3. April 14, 2015 Page 3 Growth Driver: Video Customers 8.4 million mobile video subscribers 1Q07 Penetration up 125% since 1Q06 Source: Telephia, FCC

4. April 14, 2015 Page 4 Growth Drivers: Mobile Workforce (in billions) Mobile workforce is defined as anyone who spends 20% or more time away from primary work location. Source: Industry Reports and Forrester 2006

5. April 14, 2015 Page 5 Growth in Mobile Data Usage 62% of Americans have used Mobile Data 58% have sent an SMS, emailed or browsed the internet with their phone 41% have logged onto the Internet away from home or work either with a wireless laptop connection or a handheld device. Source: Pew Internet & American Life Project, March 2008

6. April 14, 2015 Page 6 Connectivity Drivers Wireless Data Traffic (Mbps in millions) 2005 20062007 4 x between ’06 and ’07

7. April 14, 2015 Page 7 HSDPA HSUPA HSPA HSDPA+ LTE

8. April 14, 2015 Page 8 Seamless Network Access: Continue Mobile Broadband Evolution Performance Time PastPresentFuture GPRS – 25 to 40 Kbps 48 Kbps peak EDGE – 100 to 130 Kbps 237 Kbps peak UMTS – 150 to 180 Kbps 384 Kbps peak HSDPA – 400 to 700 Kbps 3.6 Mbps peak HSUPA/HSPA – 500 to 800 Kbps up 1.5 Mbps peak up (potential 5.76M) 600 to 1400 Kbps down 3.6 Mbps peak down (potential 14.4M) HSPA+ (R7) – MIMO, 64QAM Potential 11.5 Mbps peak up Potential 28 Mbps peak down LTE (R8) – 100 Mbps and beyond peak down Backward compatible migration on the existing global standard Today Speeds are typical user throughput.

9. April 14, 2015 Page 9 Mobility Assets: Faster Data Speeds Technology Road Map Peak speeds today provide a DSL-like experience LTE is designed to evolve from HSPA With HSPA R7 peak speeds of up to 28 Mbps With LTE peak speeds beyond 100 Average Downlink Speeds by Technology (Kbps) GPRS EDGE UMTS UMTS/ HSDPA R5 UMTS/ HSPA R6 20052006 2007/ 2008 20042003 2009/ 2010 UMTS/ HSPA+R7 25 100 150 400 600 700 180 130 40 1,400 28,000 1800 3600-7200 384 237 48

10. April 14, 2015 Page 10 GSM: 86% of World’s Wireless Users 200+ UMTS Operators 89 Countries with UMTS 164 Upgraded to HSPA Unmatched international roaming capabilities GSM Technologies Dominate Worldwide Source: 3G Americas

11. April 14, 2015 Page 11 Over 600 Million Wireless Broadband Connections in 2010 Source: Strategy Analytics Nov. 2006

12. April 14, 2015 Page 12 Expand 3G Wireless Broadband Network

13. April 14, 2015 Page 13 466 HSPA Devices Available Worldwide Source: GSM Association

14. April 14, 2015 Page 14 AT&T HSPA Devices Go International PC Cards Sierra Wireless AC881 Option GT Ultra Option GT Ultra Express Sierra Wireless USBConnect 881 Smartphones/ PDAs Blackjack II Samsung AT&T Tilt HTC

15. April 14, 2015 Page 15 LTE Standards status January 2008 LTE Terrestrial Radio Access Network technology specifications have been approved by 3GPP and are now under change control, leading to their inclusion in the forthcoming 3GPP Release 8. Hardware impacting L1/L2 specifications functionally frozen for both FDD and TDD. Full set of 3GPP Release 8 system specifications on track for approval during Q4 2008.

16. April 14, 2015 Page 16 HSPA/LTE Peak Throughput Evolution: Expected to double every year in Average 100 kbps 1 Mbps 10 Mbps 100 Mbps 100 kbps 1 Mbps 10 Mbps 100 Mbps 2004200520062007200820092010201120122013 HSPA DL & UL Peak Throughputs expected to double every year in average Limitations not induced by the Technology itself but time frames required to upgrade infrastructure and transport networks, obtain devices with corresponding capabilities and IOT tests UL R’99 384k HSUPA 2.0M HSUPA 5.6M HSUPA/16QAM 11M UL LTE (10MHz) 25M UL LTE (20MHz) 50M DL R’99-384k HSDPA 1.8M HSDPA 3.6M HSDPA 7.2M HSDPA 14.4M MIMO 2x2 28M MIMO/64QAM 41M DL LTE(10MHz) 140M DL LTE(20MHz) 300M

17. April 14, 2015 Page 17 LTE Mobility Advantages AT&T will continue to utilize WiMAX for applications primarily focused on fixed LTE Advantages for Mobility: Most customers, devices and applications Supports worldwide roaming Compatibility with existing AT&T Networks Designed to support efficient voice operation (VoIP)

18. April 14, 2015 Page 18 LTE Mobility Advantages Shorter frame size, lower amounts of overhead, and lower overall latency than WiMAX LTE data throughput will be equivalent to or better than WiMAX when both are operated in FDD mode LTE shorter frame size supports higher throughputs at moderate to high vehicle speeds

19. April 14, 2015 Page 19 HSDPA HSUPA HSPA HSDPA+ LTE

20. © 2008 AT&T Intellectual Property. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Intellectual Property. Questions?