Building the Mobile Internet

1. Building the Mobile Internet Introduction to Mobility

2. Mobility Market Growth in Mobile versus Fixed Broadband Subscribers

3. Millions Wi-Fi-Enabled Handsets (Millions) Growth in Wi-Fi-Enabled Handsets

4. Factors Driving Multiple Device ownership (1) • Desktop PCs: Growth will be driven by gaming as well as by watching and editing high-definition and three-dimensional video and graphics i.e. activities and processes not suited to relatively lower-powered devices like tablets, Phablets, and Smartphones

5. Factors Driving Multiple Device ownership (2) • Tablets: Growth driven by their ease of media-consumption, in addition to email access, web-browser-based services, and office productivity support.

6. Factors Driving Multiple Device ownership (3) • Phablets: Growth driven by high-quality architectures with secure data access and Enterprise Productivity support: • Also Entertainment and Games applications designed for maximum impact on these and Smartphones.

7. Other Growth Drivers • Pervasive Software Apps • Context-Aware System Architectures • Cloud Service Architectures? • ? Think of other possibilities ?

8. The Future of Mobile Markets • Device Divergence • Network Convergence? • IP Everywhere • Fixed and Cellular (Mobile) Networks: IP is the ‘fundamental Building Block’ • All data Transmission is Packet-Switched? • Three scenarios are illustrated in the next slide:-

9. Wireless Residential Gateway WiFi Enabled Tablet DSLAM Broadband Network Gateway IP/Ethernet Transport Network Internet Home ENB Packet Data Network/ Serving Gateway Correspondent Node Macro ENB Cellular Smartphone

10. Early Indication of Data Consumption Trends Average Revenue per US Mobile Subscriber

11. ON THE GO IN AN OFFICE AT HOME Location of US Mobile Internet Consumption

12. PB/Month Monthly Mobile Internet Traffic in Petabytes (Cisco VNI Forecast)

13. 4% 5% 8% 17% 66%

14. What, Where and When? We have looked at where consumers consume mobile Internet services, And also at what type of services are likely to be consumed using mobile Devices, in future. We must also consider When users access mobile services. The next slide is an representation of the traffic load in a commercial cellula network offering mobile Internet services over a 24-hour period. The figure clearly illustrates the diurnal variation of traffic load within the network, showing how the ‘data-busy’ hour is between 8.00 and 9.00 in the evening. (20:00 -21:00 hours)

15. 16:00 20:00 04:00 08:00 12:00 00:00 Example Diurnal Variation of Mobile Internet Traffic Load. mi100208

16. Towards an ‘Always-On’ scenario: Current cellular network standards allow mobile data-enabled devices to Be attached to a cellular network without allocating them an IP address. Legacy cellular networks are typically configured to automatically de-allocate a device’s IP address after a period of inactivity. The new generation of cellular standards are designed only to support always-on behaviour, and so, for example, when a device attaches to an all-IP LTE network, it must, by default, receive an IP address and be automatically enabled to send and receive IP packets. mi100209

17. Mobile Challenges The massive increase in forecast consumption of mobile services imposes serious challenges to the current Internet, its structure and in particular, to its protocols Lets look at this in a little detail…

18. Cellular Network Capacity: Key Limiters There are three key cellular characteristics: Spectrum Spectral Efficiency Frequency reuse

19. Spectrum Spectrum is a scarce resource. Higher speed transmission needs sufficient bandwidth and enough energy for wide signal propagation Governments auction the spectrum for vast sums of money. We can’t make new spectrum The laws of physics apply!

20. Spectral Efficiency (1) Efficiency of use is critical Shannon’s Law determines the maximum data transmission rate possible in ‘noisy’ transmission channels. (Ie the maximum amount of information that can be transmitted. The most advanced signal-processing techniques are at or near this limit.

21. Spectral Efficiency (2) Shannon’s Law C = B log2(1+S/N) Shannon’s limit is sometimes referred to as ‘theoretical’ It is, however, a factual law of physics. Andrew Tanenbaum states: ‘Counter-examples should be placed in the same category as Perpetual-motion machines’…!

22. Frequency Re-use Spectrum is scarce and mobile systems must re-use their allocated radio frequencies across any given cell network; Increasing capacity by re-use means smaller cells and more cell ‘tower’ transmitters.

23. Future Capacity Forecasts suggest a 39-Fold increase in demand for mobile Internet traffic (over approximately 5-years) Better use of the spectrum offers, at best, a four-fold increase in capacity in the same period.

24. Future Capacity (2) Increased use of smaller cells is the only option if the forecast demand is to be met. If the demand estimates are correct then the number of cells in any given cellular network will need to increase 10-fold to achieve the required capacity.

25. The Future Mobile Internet Scalable adoption of small-cell technologies: IEEE 802.11and ‘Home-Cells’ Massive numbers of always-on devices with single-subscription-multiple-device being the norm;. Ubiquitous access from anywhere, indoors or outdoors; Seamless service access to Video, Web, Peer-to-Peer, VoIP and Games (and more…)

26. The Internet is not Mobile..! Unfortunately the Internet does not support ‘native-mobility’ The TCP/IP stack was not designed with mobility in mind. Much has been achieved, but the approach has been by the development of ‘Tunneling Protocols’

27. The Internet is not Mobile..! Tunneling means essentially using existing IP packets as ‘wrappers’, and running everything over the existing structure.

28. The Internet is not Mobile..! However, we shall see that seamless, real-time mobility requires that ‘sessions stay alive’ when devices move between different types of access networks and across networks belonging to different operators.

29. The Internet is not Mobile..! What is required is the capability to implement what has become known as ‘Session-mobility’. This is a a very tough challenge; However, if it can be achieved, the potential benefits for communications is enormous.

30. The Internet is not Mobile..! To understand the problem we need a detailed understanding of the way that the Internet works. We need to appreciate the limitations of current Mobility ‘solutions’; Then we can begin to consider new approaches to building a truly ‘Mobile Internet’

31. References Texts: Building the Mobile Internet Grayson et. al. Computer Networking: A top-Down Approach 6th ed. Kurose and Ross Other Reading Computer Networks 5th ed. Andrew Tanenbaum Claude E. Shannon Shannon’s Law (See next slide)

32. The Ultimate Limit:Shannon’s Law Shannon’s law is simple and elegant: It states that C = B log2(1 + S/N) where C is the capacity of the channel in bits per second B is the channel bandwidth in Hertz S is the average received signal power over the bandwidth N is the average noise or interference power over the bandwidth, measured in watts (or volts squared); and S/N is the Signal-to-Noise ratio (SNR) So, for example, if we have a communications channel with a signal-noise ratio of, say 30db, then the signal is 100 times stronger than the noise and the S/N = 1000 If the available bandwidth is 100 MHz, (100,000,000 Hz), then the channel can transmit 996,722,625 bits per second. i.e. 996 Mbps. Almost 1Gbps. Note that an S/N of 1000 is very high and very difficult to achieve. In a wireless network S/N varies widely. Work out the bandwidth needed to provide a 1Gbps bit rate on a Wi Fi network if the S/N ratio is 100

33. The Ultimate Limit:Shannon’s Law Exercise: Work out the bandwidth needed to provide a 1Gbps bit rate on a Wi Fi network if the S/N ratio is 10 Then, In a wireless network S/N varies widely. Work out the bandwidth needed to provide a 1Gbps bit rate on a Wi Fi network if the S/N ratio is 2