tackling protocol diversity: isoc@ietf panel at ietf 93

www.internetsociety.org

Tackling Connectivity Diversity:Protocol Challenges for Constrained Radio Networks and Devices

Olaf Kolkman, Moderator

Chief Internet Technology Officer

The Internet Society

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We are…

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Not at the IETF

Taking discussion up a level

Taking any identified work items to the appropriate IETF WGs

“On the air”

Streaming

Recording

Stopping at 12:45pm so you can all get back to the IETF…


Agenda outline

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Overview

Panelists’ introduction

Framing discussion

Open mic


The Panel

Olaf Kolkman (Moderator)

Ted Hardie

Blake Matheny (Facebook)

Henning Wiemann (Ericsson)


Today’s discussion

Disconnect between application development environments and application use environments

Handsets

Networks

Does infrastructure need to change?

Is this a transient condition?

Is there a need for better design to cope with connectivity diversity?

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Global Internet Report

Some charts from the Internet Society’s Global Internet Report 2015

More at: http://www.internetsociety.org/globalinternetreport/

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http://www.internetsociety.org/globalinternetreport/


Proportion of population covered by at least 3G

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The Internet Society8


The Digital Divide

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The Internet Society10


Panelists’ introduction

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Characteristics of Mobile Broadband Connections

… as seen from IP and above

Henning WiemannEricsson Research3GPP RAN2 Chairman

Characteristics of Mobile Broadband | Public | © Ericsson AB 2015 | 2015-07-20 |

› Packet Loss Rate seen on IP layer: < 10-6

–ARQ to avoid that TCP interprets transmission losses as congestion

› Latency (RTT) in the order of tens of ms–Spikes due to error correction (ARQ)–Spikes due to Connection Establishment and DRX (see next slide)

› Data Rates vary depending on channel conditions, network load, total carrier bandwidth, deployed features…– LTE today: ~100 kbps (at the coverage edge) to ~300 MBps

(specs allow already much higher rates)

PerformanceData Rates, Latency, Loss Rate

Be prepared for varying data rates!Latency is low but shows some spikes!


› Discontinuous Reception (DRX) to save UE battery–Allows UE to switch-off receiver chain after short inactivity–Network initiated traffic observes additional delays (typically 0.05 to 1s)

› Radio Connection released upon longer inactivity– Further decreases battery consumption and control signaling–But requires additional control signaling and delays when

connection is established again for the next packet burst

Power ConsumptionImpact to Performance & Reachability

Every “Keep-Alive” is costly if it forces the UE to wake-up from DRX or to establish a new Radio Connection!


› Data Rates will still vary– Aiming at high data rates in wider areas (e.g. massive beamforming)

–Connectivity in very challenging coverage conditions (at least for low data rate Internet-of-Things applications)

– Even higher peak data rates (up to several tens of GBps)

› Latency Reductions– Aiming initially at a reduction by a factor ~5-10– Even lower latency is targeted for latency critical applications

› Low loss rates should remain to be low– To ensure that TCP can utilize the high data rates– But costly in terms of memory (Packet-Delay-Budget)

And in Future?


Blake MathenyFacebook

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Tension among competing optimizations

Building blocks

Is it better for applications or systems to use multiple building block protocols that can be swapped in and out, or single protocols with a wide range of applicability?


Some aspects to consider

Approaches taken by application developers to deal with terminal and connectivity diversity

Considerations for protocol developers

The impact of restricted connectivity on user behavior

Design principles that could be extrapolated from the data and the technical responses to date

Interactions between power management and connectivity management


The Panel

Olaf Kolkman (Moderator)

Ted Hardie

Blake Matheny (Facebook)

Henning Wiemann (Ericsson)