Building the Mobile Internet

Introduction to Mobility

Growth in Mobile versus Fixed Broadband Subscribers

Mobility Market

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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

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.

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.

Other Growth Drivers

• Pervasive Software Apps

• Context-Aware System Architectures

• Cloud Service Architectures?

• ? Think of other possibilities ?

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:-

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Voice Data

Early Indication of Data Consumption Trends

Average Revenue per US Mobile Subscriber

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Monthly Mobile Internet Traffic in Petabytes (Cisco VNI Forecast)

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 mobileDevices, in future.

We must also consider When users access mobile services. The next slide is an representation of the traffic load in a commercial cellulanetwork 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)

Global Mobile Data Traffic, 2014 to 2019

Overall mobile data traffic is expected to grow to 24.3 exabytes per month by 2019, nearly a tenfold increase over 2014.

Mobile data traffic will grow at a CAGR of 57 percent from 2014 to 2019

Source: Cisco VNI Mobile, 2015

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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 adevice’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.

Mobile ChallengesCisco Virtual Network Forecast:Read this Cisco White Paper:

http://www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-networking-index-vni/white_paper_c11-520862.html

Take time to study this in detail…

Cisco Forecast in 2014:

Cisco Forecast in 2015

What does this mean?

• 15.9 Exabytes of Mobile Data Traffic:

• 24.3 Exabytes of Mobile Data Traffic:

Bytes ??? (Disk Storage)

• Kilobyte = 1000 bytes

• Megabyte = 1000 KBytes

• Gigabyte = = 1000 MBytes

• Terabyte = 1000 GBytes

• Petabyte = 1000 TBytes

• Exabyte = 1000 Pbytes = ?? Bytes

Bytes (Virtual Storage) ???

• Kilobyte = 210 bytes = 1024 bytes

• Megabyte = 220 bytes 1048576 bytes

• Gigabyte = 230 bytes = 1073741824 bytes

• Terabyte = 240 bytes = ?

• Petabyte = 250 bytes = ??

• Exabyte = 260 bytes ≈ 1.1529 x 1018 bytes

Mobile Consumer Trends

• http://www.cisco.com/c/en/us/solutions/service-provider/vni-service-adoption-forecast/index.html

Cellular Network Capacity: Key Limiters

There are three key cellular characteristics:

•Spectrum

•Spectral Efficiency

•Frequency reuse

The speed at which data can travel to and from a mobile device can be affected in two places:

the infrastructure speed capability outside the device, and

the connectivity speed from the network capability inside the device (Figure 22). These speeds are actual and modeled end-user speeds and not theoretical speeds that the devices, connection, or technology is capable of providing.

Several variables affect the performance of a mobile connection: •Rollout of 2G/3G/4G in various countries and regions, •technology used by the cell towers, •spectrum availability, •terrain, •signal strength, and •number of devices sharing a cell tower.

•The type of application being used by the end user is also an important factor. Download speed, upload speed, and latency characteristics vary widely depending on the type of application, be it video, radio, or instant messaging.

Mobile ChallengesThe 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…

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!

Spectral Efficiency (1)

• Efficiency of use is critical

• Shannon’s Law determines the maximum data transmission rate possible in ‘noisy’ transmission channels: i.e. the maximum amount of information that can be transmitted.

• The most advanced signal-processing techniques are at or near this limit.

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’…!

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.

Future Capacity• Forecasts suggest a 39-Fold

increase in demand for mobile Internet traffic:

(over approximately 5-years

2013 - 2018)

• Better use of the spectrum offers, at best, a four-fold increase in capacity in the same period.

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.

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…)

The Future Mobile InternetThe Key problems and Challenges:• Spectrum Limitation is clearly a

major problem:

• A second problem, just as challenging is the inherent design of the Internet and its primary protocols

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’

The Internet is not Mobile..! • Tunneling means essentially

using existing IP packets as ‘wrappers’, and running everything over the existing structure.

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.

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.

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’

Broadband Network Gateway

DSLAM

Wireless ResidentialGateway

(Access Point)

InternetIP/Ethernet TransportNetwork

Packet DataNetwork/ Serving

GatewayMacroENB

WiFiEnabled

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HomeENB

CellularSmartphone

Correspondent Node

Fixed-Cellular Convergence: Three Scenarios:

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)

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 1000 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

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