This document summarizes a presentation given by Dean Bubley at the eComm Europe 2009 conference about issues with supporting voice services on LTE networks. It notes that 3GPP has standardized IMS voice (MMTel) and circuit switched fallback for LTE, but both have significant drawbacks. IMS voice has not gained traction, while circuit switched fallback requires extra network components and drops the data connection. Supporting SMS on LTE was also an afterthought and led to interoperability problems. As a result, the document argues that LTE networks may not be ready to fully replace 3G networks for providing voice and messaging services until these issues are resolved.

1. 2009 | Westergasfabriek | Amsterdam | http://eComm.ec

2. Is LTE being held hostage by voice telephony?
eComm Europe 2009, October2009
dean.bubley@disruptive-analysis.com

3. About Disruptive Analysis
 Analyst house & consulting firm
 Founded by Dean Bubley
 Blog at disruptivewireless.blogspot.com
 Covering Mobile VoIP since 2001
 Regular focus on the links between innovative mobile network
technologies & the impact on devices and applications
 New network technologies always have some implications for the
handset beyond the radio
 If user behaviour changes, the handset’s behaviour & design should
change too
 Published “VoIPo3G” report Nov 2007
Oct 2009 Copyright Disruptive Analysis Ltd 2009

4. LTE – the latest, greatest mobile standard!
Oct 2009 Copyright Disruptive Analysis Ltd 2009

5. Options for LTE voice
3GPP
 IMS Voice, aka MMTel (Multimedia Telephony) standardised
 Circuit Switched Fallback solutions
 VoLGA
 NSN Fast Track Voice
 Mavenir / Acme Packet
 Third-party VoIP on LTE data
…. or stick with HSPA
Oct 2009 Copyright Disruptive Analysis Ltd 2009

6. IMS… dead, but nailed to the perch of LTE
3GPP LTE
Mobile IMS
Oct 2009 Copyright Disruptive Analysis Ltd 2009 Fjords, aka RCS

7. Circuit switched fallback (CSFB)
 So bad, it’s almost as if it’s designed to make IMS look good
 Needs 2G / 3G coverage in same place
 Extra seconds for call set-up (great for emergency calls)
 Drops the data connection
 Not great for multi-tasking
 Not great for voice+data mashup applications
 Not great for background apps
 Nightmare for femtocells
 Extra capex on the network side
Oct 2009 Copyright Disruptive Analysis Ltd 2009

8. SMS on LTE
 Almost completely forgotten until it was too late
 Original expectation was the early LTE devices would be data only –
laptops, dongles, MIDs
 Only handsets need SMS, right? It can wait…..
 Radio standards guys failed to realise that SMS is used for:
 Roaming lists
 Advice of charge
 Device management
 …. and 10-20 other IT systems for mobile broadband.
 Panicked rush to do a workaround called SMS-over-SGs
 Tied into CSFB but doesn’t force LTE-> 2G / 3G
 Might even work… eventually
Oct 2009 Copyright Disruptive Analysis Ltd 2009

9. Recipe for disaster
 Totally new radio network
 Shift of #1 and #2 source of $$ from CS to VoIP
 No workable standard
 No handsets
 No clear specifications
 Multiple options = interoperability & roaming nightmare
 Forgot about SMS entirely
 Still batting around options at end-2009
 LTE in 2010? ….. Or maybe 2014 is more likely?
… or just stick with HSPA+ in 2.6GHz, 900MHz etc?
Oct 2009 Copyright Disruptive Analysis Ltd 2009

10. www.disruptive-analysis.com
disruptivewireless.blogspot.com
dean.bubley@disruptive-analysis.com
+44 (0) 7941 100016
Oct 2009 Copyright Disruptive Analysis Ltd 2009

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2009 | Westergasfabriek | Amsterdam | http://eComm.ec