Transcript Push To Talk Over Cellular: Still Searcing The Flow Of Success

Push To Talk Over Cellular: Still
Searcing The Flow Of Success
Research Seminar on Telecommunications Business II
Seminar presentation 12.4. 2005
Raili Koivisto
Helsinki University of Technology
Contents
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Introduction
Benefits for end-users and operators
Technology options and substitutes
Performance
Vendor and operator strategies
Pricing
Regulation
Conclusions
Introduction
• PTT is a half-duplex voice service
• PTT available since World War II with
limited coverage but minimum charges
• In 1996 Nextel begins to rollout iDEN
• PTT in cellular networks is called Push-ToTalk over Cellular (PoC)
PoC
PoC building blocks
• PoC Server for floor control and speech
traffic
• SIP IP Core for signalling
• GLMS for group management
• Presence Server
• PoC Client in terminal
Benefits for end-users
• Immediate wireless contact to a predefined person or group
• Worldwide network
• Suitable for group of friends, hunters,
small businesses
Benefits for operators
• Enables to compete with existing PTT
services
• Enhanced voice services
• New usage models -> more usage ->
increased ARPU in developed markets
• New users in developing markets
• Efficient way of using network resources
Technology options
• OMA PoC by Ericsson, FastMobile, Motorola, Nokia,
Siemens, Sonim
– CDMA, GSM, WLAN, client-only implementation
– IMS architecture based
• iDEN by Motorola
– Fast ”chirp to talk” times
– Proven solution
• QChat by Qualcomm
– CDMA only
– BREW client-only implementations
• Circuit-based PoC by Kodiak Networks
– Network agnostic
– Circuit connection after call set-up -> cost, radio resource use
Substitutes
• Conference call
– No savings in cost or radio resource, slow to set up
• Fastchat
– Client integrated in Symbian
• SKYPE + PDA + WLAN
– Peer-to-peer, no central host, limited user base
– Smaller savings in cost or radio resource
Push-To-Talk over Bluetooth
– Short range only
– Free of charge
– Hybrid with PoC possible
• Instant Messenger solutions
– Limited terminal selection
Performance
• Circuit-switched PoC over 6x more expensive
than PoC over GPRS
• PoC over GPRS 5x more efficient, PoC over
EGPRS 14x more efficient than over GSM
• Latencies remarkable in GPRS
• Voice quality on GSM level, BER quite high
• Performance depends on end-to-end tuning
Vendor strategies
• Several camps beside OMA
standardization work, other technologies
also further developed
• Use of pre-standards to colonize markets
• Clients available in phones
• Trials with operators ongoing
Operator strategies
• 35 operators using pre-standard solutions
now, 14 of them using Kodiak in CS
• Others waiting for OMA standard?
– Or thinking positioning/pricing/target groups?
– Or gathering money for new investments?
– Or denying to cannibalize existing business?
• Charging requires interconnection
agreements
• Lacking walkie-talkie culture in Europe
Pricing
• OMA architecture supports several pricing
methods
• In US subscription fee includes certain no
of minutes
• In Australia normal call charge doubled
• Simple pricing model encourages users
• Pricing now – pricing in future
Regulation
• Is PoC a voice service which should be
regulated (legal interception)?
• EU wants to encourage, not restrain
diffusion of VoIP, FCC on same way but…
• Privacy of user data, presence, location,
group lists has to be regulated
• Regulation needed for competition issues
• Not applicable for emergency services
Conclusion
• Technology push but no dominant design yet
• High performance and worldwide interoperability
require standard based solutions
• Proven use case in US but does it work in
Europe or Asia?
• Is there enough attractiveness before
multimedia convergence and virtual reality
solutions?