1 THE ROLE OF VOIP: FUTURE EVOLUTION PATHS OF VOICE COMMUNICATIONS Timo Smura & Heikki Hämmäinen Helsinki University of Technology Networking Laboratory P.O. Box 3000 FIN HUT, FINLAND Abstract This paper analyzes the future evolution paths of voice communications services. The focus is on defining the role and success potential of different types of VoIP services, ranging from IM-like doit-yourself VoIP to operator-managed VoIP services with QoS guarantees and PSTN interconnectivity. The paper proposes a simple model for voice service classification, and analyzes the end-user value and market potential of different VoIP services classes. The concepts of network effects and disruptive technologies form the framework for analyzing the evolution paths of voice communications from circuit-switched networks to VoIP services. Substitution effects between fixed, wireless, and mobile domains are recognized as an important factor affecting the success potential of VoIP services. Based on the discussion, some remarks are made regarding the QoS and pricing issues of different types of VoIP services. Key Words VoIP, instant messaging, disruptive technology, network effects 1. Introduction During the past decade, the communication habits of people have changed tremendously. Technologies such as , mobile telephony, and SMS messaging have become an important part of every-day communication for the majority of the people in developed countries. Emerging technologies such as MMS, instant messaging, push-to-talk, and different types of VoIP services are currently being taken into use in the markets. All of these technologies are generally serving the same purpose, the inherent desire of people to communicate with each other.
2 Figure 1 illustrates these different communications means. In the figure, person-to-person communications services are placed on a matrix based on two different qualities. Firstly, the services are divided into three groups: mailing, messaging, and calling, based on the immediacy of the communication. Secondly, the services are differentiated on the basis of the content that can be conveyed by them, i.e. text, images, voice, or video. Mailing Messaging Calling Traffic volume increases Value per bit decreases Video Voice Image Text Fax Pushto-talk Voic Multimedia msg Text msg Instant msg Chat Video call Voice call Latency decreases Value increases Figure 1: Classification of person-to-person communications services In the figure, the latency requirements of the services become stricter when moving from left to right (from mailing to calling), and the end-user value increases. Capacity requirements increase when moving from bottom to top (from text to video), whereas the end-user value per transmitted bit usually decreases. Other dimensions of end-user value not shown in the figure include e.g. mobility and reachability of the users, as well as the technical quality of the calls. Mobility increases the value of telephony services by allowing people to maintain their ability to communicate regardless of time or place. This anywhere, anytime dimension removes the location dependence of voice communications and brings value e.g. in increased productivity of business users. The other dimension of mobility is that it makes people more reachable: most people are always carrying mobile phones and rarely turn them off. Increased reachability increases the network value as the number of on-line users in the network increases. In addition to fixed and mobile networks, there exist a number of wireless technologies that provide local mobility inside e.g. a home or office building. Cordless phones utilizing radio technologies such as DECT can be used as a wireless extension to fixed PSTN networks. In packet-switched IP
3 networks, Bluetooth and various WLAN technologies can be utilized. Table 1 shows the categorization and examples of different technologies in different network domains. Table 1: Examples of technologies in different network domains Fixed Wireless Mobile Circuit-switched PSTN, ISDN DECT Bluetooth GSM UMTS CS Packet-switched ADSL Cable WLAN Bluetooth GPRS/EDGE UMTS PS The technical quality of voice communications depends on the codecs used in the terminals and on the QoS characteristics of the networks (e.g. available data rates, delay/jitter values, and experienced packet loss). MMS and non-optimized push-to-talk messaging services may experience end-to-end delays of over 10 seconds. Push-to-talk over Cellular (PoC) services specified by the Open Mobile Alliance (OMA) are required to have significantly smaller end-to-end delays of less than 1.6 seconds, whereas the reference end-to-end delay limit for good-quality circuit-switched phone calls is 150 milliseconds. (OMA 2004, ITU-T Rec. G.114) 2. Conceptual framework 2.1 Network effects Network effects, as defined by Katz & Shapiro (1985), are present in goods for which "the utility that a given user derives from the good depends upon the number of other users who are in the same "network" as is he or she". Person-to-person communications is a perfect example of services experiencing network effects. For more detailed discussion on the terminology and different types of network effects, see Liebowitz & Margolis (1994). Because of the network effects, the value of a certain network service increases with the number of people using it. Three different laws have been proposed for modeling the growth of network value as a function of the number of users. Broadcasting services such as news sites aimed at individuals benefit from additional users in a linear way, following the so-called Sarnoff s Law (value ~ n). Services aimed at facilitating transactions, such as marketplaces and auction sites, follow the Metcalfe s Law where the network value grows as approximately square of the number of users (value ~ n 2 ). Services aimed at building communities follow the Reed s Law, where the value grows in exponentially due to the group-forming dynamics (value ~ 2 n ). (Reed 1999)
4 The network effects related value of VoIP varies considerably between different types of VoIP services. Some services provide interconnection to traditional PSTN and mobile networks, whereas some are totally independent and based on proprietary technologies with no interoperability or interconnectivity. Furthermore, some services are available only on fixed networks whereas some are enabling use also on wireless and mobile devices. Technical fragmentation decreases the value of network services. A good example is the current instant messaging (IM) market, which is dominated by three major players providing proprietary services: Yahoo!, AOL, and Microsoft. In the consumer market, none of the three services are interoperable, which reduces the value of all. As a side-effect, new multi-network IM services have emerged in the market, integrating many different IM protocols in one software client and allowing users to connect to many IM services using a single user interface. Interconnection arrangements increase the value of network services. VoIP services interconnecting with PSTN and mobile networks have higher value for the users, as they provide the ability for people to communicate also with non-voip users. Many of the VoIP services provided by incumbent telecom operators are providing interconnectivity with traditional services. User on-line time is also an important variable having an effect on the value of network services. Although the fixed telephone network reaches the majority of households and businesses in developed countries, the users are not reachable when outside their homes or offices. Mobile networks providing effectively ubiquitous access have a positive impact on the value of telephone networks, making users in practice always on-line. 2.2 Technological innovation and disruptive technologies VoIP services are currently taking over markets traditionally served by circuit-switched PSTN networks. This kind of technological discontinuity is inevitable in all industries and markets, as new innovations replace existing technologies. Issues related to technological evolution and discontinuities as well as adoption of new technologies and innovations have been studied extensively in economics and management sciences. For a literature review on typology and terminology of technological innovation, see (Garcia & Calantone 2001). A useful concept for analyzing different types of VoIP services is the one of sustaining and disruptive technologies and innovations by Christensen (1997). Sustaining technologies are such that improve the performance of established products along dimensions that customers have historically valued. Disruptive technologies, on the other hand, are initially underperforming the established products when measured by the historically valued metrics. They have other features that are initially
5 valued by a small amount of customers either in a new market or at the low end of the existing market. Products based on disruptive technologies are typically cheaper, simpler, smaller, and often more convenient to use. Figure 2 illustrates the difference between of sustaining and disruptive technological change. Product performance Performance demanded at the high end of the market Disruptive technological innovation Progress due to sustaining technologies Progress due to sustaining technologies Performance demanded at the low end of the market Time Figure 2: Sustaining and disruptive technological change (Adopted from Christensen 1997) As shown in the figure, technologies can progress faster than market demand. The performance of products in the market eventually overshoots the market, giving customers more than they need and are willing to pay for. This leaves space for initially underperforming disruptive technologies that may be fully competitive in the future. (Christensen 1997) Christensen & Raynor (2003) distinguish between two different types of disruptions: low-end and new-market. Low-end disruptions attack the least profitable and most over-served customers at the low end of the original value network. New-market disruptions, in contrast, compete against nonconsumption, creating a new value network. For recognizing the low-end and new-market disruptive potential, Christensen & Raynor introduce a set of questions to be considered. This three litmus test is illustrated in Figure 3.
6 New-market test Is there a large population of people who historically have not had the money, equipment, or skill to do this thing for themselves, and as a result have gone without it altogether or have needed to pay someone with more expertise to do it for them? and/ or To use the product or service, do customers need to go to an inconvenient, centralized location? and Low-end test Are there customers at the low end of the market who would be happy to purchase a product with less (but good enough) performance if they could get it at a lower price? and Can we create a business model that enable us to earn attractive profits at the discount prices required to win the business of these overserved customers at the low end? and Litmus test Is the innovation disruptive to all of the significant incumbent firms in the industry? Figure 3: Three litmus test for recognizing disruptive technologies (based on Christensen & Raynor 2003) In our view, the emergence and evolution of different types of VoIP services include both sustaining and disruptive types of technological advances, discussed in more detail later. From the point of view of incumbent telecom operators, it is important to recognize the disruptive potential of different VoIP services, as they might provide possibilities for new entrant firms to overtake the businesses of the incumbents. 3. Different classes of VoIP services When discussing VoIP services, extra caution is required to separate apples from oranges. A number of different types of VoIP services exist, with different players managing the required network infrastructure and servers. Differences exist also e.g. in the pricing schemes, addressing models, level of interconnection to PSTN and mobile networks, and in the level and effects of regulation. The scope of this paper is limited to VoIP services actually used and experienced by consumers and business users. The use of IP networks as part of operators backbone networks or as trunk lines between privately owned PBXs is out of scope. Accordingly, we recognize three fundamentally different classes of VoIP, named after an analogy to existing, well-known services and systems. The classes are PBX-like VoIP, PSTN-like VoIP, and IM-like VoIP, and their characteristics are summarized in Table 3.
7 Table 2: Characteristics of different classes of VoIP PBX-like VoIP PSTN-like VoIP IM-like VoIP Examples Cisco CallManager, Vonage, Net2Phone (U.S), Ipon, Sonera Puhekaista (Finland) MSN Messenger, ICQ, Yahoo! Messenger, Skype, AOL Instant Messenger Domains Fixed, Wireless Fixed, Wireless Fixed, Wireless, Mobile Typical users Managed by Typical pricing scheme Global phone numbers allocated to users Large enterprises, SMEs Corporation (IP PBX) / local service provider (IP Centrex) Free calls inside the LAN. PSTN-like pricing on outgoing calls. Consumers, Small businesses Broadband ISP / local service provider Free / low-cost calls to other VoIP users. PSTNlike pricing on outgoing calls. Consumers Global service provider Free calls to other VoIP users. PSTN-like pricing on outgoing calls. Yes Yes No PSTN-interworking Two-way Two-way Only outgoing / none QoS control High Medium / Low Low Regulation Regulated as private ECS Under discussion. (Regulated as PATS in Finland) Not regulated 3.1 PBX-like VoIP PBX-like VoIP systems are deployed by companies as replacements to existing circuit-switched PBX and Centrex systems. Analogous to the circuit-switched systems, companies can manage the VoIP service by themselves or outsource the management to specialized service providers. The alternatives are commonly described as IP PBX and IP Centrex, respectively. Many of the corporate VoIP systems are based on standardized technologies and protocols, but the systems usually have proprietary enhancements and extensions and are generally non-interoperable between manufacturers. In corporate VoIP systems, the company-internal voice calls inside office buildings and between branch offices are carried using an IP-based data network. External calls to and from the PSTN networks are interconnected through VoIP gateway devices. In the internal IP network, it is possible to use either special VoIP phones or software clients installed in PCs, and some manufacturers have introduced also WLAN-enabled VoIP handsets. In corporate VoIP systems the IP network is private. Therefore, the QoS level of the VoIP calls can be more easily controlled and managed than in public VoIP services.
8 3.2 PSTN-like VoIP PSTN-like VoIP class includes services targeted mainly for households as a replacement for the primary or secondary fixed PSTN lines. The services are provided by broadband ISPs as well as independent third-party service providers. Subscribers are allocated phone numbers from national numbering plans, and the services provide two-way interworking between IP and PSTN networks. The subscribers can connect to the services in three ways, either by using special adapters to connect regular analog phones to the broadband modems, by using special VoIP phones, or by installing a socalled soft-phone software client on their PCs. It is also possible to connect cordless phone systems to the adapter, or use WLAN-enabled VoIP phones. PSTN-like VoIP services are straightforwardly competing with the traditional PSTN telephony services. The pricing of IP-to-PSTN calls is driven by the terminating costs of the PSTN network operators, whereas intra-provider IP-to-IP calls typically carry lower prices or are completely free-ofcharge. An important differentiator to traditional PSTN services is the inherent portability of the VoIP service, meaning that subscribers can connect their phone adapters to any location provided with Internet access, and place and receive phone calls from their own number. The regulation of PSTN-like VoIP services is currently an open topic. For an overview of the VoIPrelated issues in the European regulatory framework, see (Analysys 2004). 3.3 IM-like VoIP The third class consists of instant messaging (IM) like VoIP services. The services are typically provided by a global service provider as a part of broader instant messaging service integrating e.g. text messaging, video calls, and file transferring. The most popular services are currently Yahoo! Messenger, MSN Messenger, AOL Instant Messenger, ICQ, and Skype. The services are typically based on proprietary non-interoperable technologies and protocols. IM services require a special software client to be downloaded and installed on PCs or other computing devices such as PDAs or smart phones. Before being able to communicate with each other, users have to log in to the IM service, which can be running either on centralized servers or be decentralized using a peer-to-peer type of approach. The IM service keeps the presence state (e.g. online, busy, away, out-to-lunch) of each user, and communicates it to other users. Communications is possible in one-to-one or one-to-many fashion, and usually only between people that have authorized each other for the communication. The users are not associated with any global phone numbers as is the case in the other classes, implicating that although IP-to-PSTN calls may be possible, PSTN-to- IP calls are not.
9 The most appealing feature of the IM-like VoIP services is that they are usually free to use, i.e. the user only has to pay for the Internet access. Instead of charging the users for the VoIP services, the service providers are currently relying on other business models, such as selling advertisement space and charging for calls to PSTN networks. In most countries, IM-based VoIP services are currently not facing any regulatory requirements. 4. Evolution paths and transition effects In this section, possible evolution paths of voice communications are presented and analyzed. The big picture underlying the discussion is shown in Figure 4. Fixed Wireless Mobile Consumer Corporate Corporate LAN VoIP Circuit-switched telephony PSTN-like VoIP IM-like VoIP IP PBX / IP Centrex PBX / Centrex calls PSTN calls VoIP calls Skype calls using WLAN using DECT using WLAN using WLAN 1 4 Mobile VoIP, (PoC) GSM calls 5 5 Mobile VoIP, (PoC) 4 3G CS calls Skype over Mobile Figure 4: Evolution paths of voice communications The arrows in Figure 4 illustrate our view on the most important future evolution paths in the voice communications market. Today, most of the voice calls take place in the circuit-switched networks. A major transition is happening from fixed to mobile networks (arrow 1), commonly known as fixedto-mobile substitution. Another clearly visible trend is the transition of corporate voice traffic from circuit-switched to VoIP systems (arrow 2). In the consumer market, PSTN-like VoIP services are being offered by both incumbent operators and new players (arrow 3). Independently from this evolution, IM-like VoIP is also becoming more and more popular, first in fixed and later in mobile networks (arrows 4). Finally, there exists a possible evolution path towards operator-driven mobile VoIP services, both for the consumer and corporate PBX markets (arrows 5).
10 In the following subsections, the most visible ones of these evolution paths are discussed in more detail. The concepts of network effects and disruptive technologies introduced in Section 2 are used as a basis for the discussion. Selected examples from various markets are used to clarify and illustrate the evolution paths. 4.1 Fixed-to-mobile substitution Fixed-to-mobile substitution (FMS), meaning the substitution of subscriptions and calls from fixed to mobile networks, is a major trend acting as barrier and competitor to different VoIP evolution paths. In the European Union, the penetration of mobile subscriptions is already over 80% and there is evidence that fixed-line calls are increasingly being replaced by mobile calls. Finland has experienced the effects of fixed-to-mobile substitution earlier than most of the other European countries. Figure 5 shows the evolution of the number of calls and call minutes originated in fixed and mobile networks during the years The FMS effect is clearly visible from year 2000 onwards. Number of calls (Millions) Number of minutes (Millions) GSM originated calls GSM originated minutes Fixed originated calls Fixed originated minutes Figure 5: Numbers of outgoing calls and call minutes from fixed and mobile phones in Finland (Source: Statistics Finland 2004) Network effects act as an evident driver for FMS, as discussed earlier in Section 2.1. Mobile subscribers are usually carrying the phones all the time and rarely turn them off. Whenever there is a need for a person to either place or receive a phone call, the mobile phone is available, if any. Although the fixed-line possibility might exist, the convenience of using a single, assured way of communicating starts to dominate. Furthermore, as the fixed-to-mobile tariffs are often higher than
11 mobile-to-mobile tariffs, subscribers have an incentive to start using only mobile phones for voice calls. Some recent developments in wireless technologies such as WLANs can be seen as a barrier to FMS. Although users might prefer using a single mobile device for placing and receiving phone calls, the calls do not necessarily have to utilize mobile networks. In locations where WLAN or Bluetooth coverage is available, dual-mode handsets could use these unlicensed networks for VoIP calls and data sessions. The unlicensed networks can be privately owned by companies and consumers, but also by the mobile operators. Interworking between cellular and unlicensed networks is currently developed in 3GPP as well as in a recent industry initiative called Unlicensed Mobile Access (UMA 2004). 4.2 Evolution towards PBX-like VoIP The second evolution path already clearly visible in today s communication market is the substitution of corporate PBX systems from circuit-switched to IP-based technologies. This evolution path is competing with the fixed-to-mobile substitution trend, and the two can be seen as barriers to one another. Common arguments for PBX-like VoIP systems include the reduced cost of building and maintaining a single, integrated voice and data network infrastructure, as well as the possibility to use new, enhanced services provided by the VoIP system. Furthermore, the easy portability of VoIP terminals from one physical location to another reduces administrative work-load costs. From the point of view of network effects, PBX-like VoIP systems have very similar characteristics to traditional PBX and Centrex systems. The systems provide a private, company internal addressing space, as well as interconnection to global PSTN networks using globally addressable phone numbers. The emergence of mobile handsets supporting WLANs and VoIP will improve the mobility and reachability of VoIP users, much in the same way as DECT in the circuit-switched systems. When applying the concepts of disruptive technologies on the PBX-like VoIP systems, we conclude that the systems present more sustaining than disruptive type of technological evolution. The systems are not conforming to the definition of new-market disruptions, as they are fulfilling essentially the same needs than traditional PBXs. The systems are not a good fit for low-end disruptions either, as the value proposition is usually to provide more advanced PBX features than in circuit-switched systems.
12 4.3 Evolution towards PSTN-like VoIP PSTN-like VoIP services have recently emerged in the consumer and SME market, providing an alternative to traditional PSTN services. The services are driven by the increasing penetration of broadband Internet subscriptions and competitive offers of new players in the service provider market. The services are provided by broadband ISPs (both incumbents and new entrants) as well as third party service providers providing only the VoIP service on top of Internet access service provided by someone else. The market for PSTN-like VoIP services is still in its infancy, and the services have not yet achieved very significant user bases. In the U.S., Vonage has currently over lines in service and is adding about new lines per month (Vonage 2004). In June 2004, or 25 percent of the Finnish households were subscribing to broadband services, and the number of PSTN-like VoIP lines was approximated to be (Tikkanen et al. 2004). The PSTN-like VoIP services can straightforwardly utilize the network effects of interconnection to global PSTN networks. Phone numbers are allocated to all the subscriptions from the national numbering plans, thus making the subscribers globally reachable. VoIP software installed in WLANenabled terminals can be used to improve the mobility and reachability of the service, and it is also possible to connect a circuit-switched cordless phone system to the service using the VoIP adapter. In our view, the PSTN-like VoIP service represents more a sustaining than disruptive type of technology. It does not have potential to be a new-market disruption, as the penetration of similar PSTN and mobile services is already almost 100% among the households and SMEs in the developed countries. It could pass the low-end disruption test, as there likely exists subscribers that would be happy to subscribe to a lower-cost telephony service, provided that they have an existing broadband subscription. However, the PSTN-like VoIP services are certainly not disruptive to all the incumbent operators of the telecom industry, as many of these are providing these kinds of VoIP services themselves. Therefore, the services fail the final litmus test, and can not be considered to be a disruption. 4.4 Evolution towards IM-like VoIP In contrast to the other, generally sustaining types of evolution paths, the IM-like VoIP services represent a more disruptive type of technology evolution. Whereas the other VoIP types are more strongly tied to the business models and value networks of the traditional telecom industry, IM-like services have their roots in the Internet and web world. The IM-like services are characterized by the presence-based addressing of users. The users are reachable and can reach other users only when
13 logged in to the service, and are not allocated any global phone numbers. Therefore, the control and management of the service and its features is extremely centralized to the hands of few global players. The most powerful players in the market include Microsoft, Yahoo!, and AOL, as well as a smaller new entrant Skype. Usually, the IM services use a centralized directory for the associating static usernames and identities with dynamic IP numbers of users. These directories also keep track on the presence state of the users. Skype differs from the other services in that it is not using this kind of a central directory. Instead, it is relying on a decentralized directory, utilizing a peer-to-peer type of multi-tiered network architecture. A certain amount of users act as so-called supernodes, communicating with each other so that each one has a full knowledge of all available users. This is claimed to improve the scalability of the system and bring cost savings (Skype 2004). IP-to-IP calls using IM services are typically free, and some of the services provide also a possibility to make IP-to-PSTN calls with competitive tariffs. PSTN-to-IP calls are not possible, as the users are not identified by any global phone numbers. Despite this shortcoming, clear evidence of demand for these kind of services exists. As an example, during its first year of operation Skype was downloaded by over 12.9 million different users, and the number of simultaneous users currently exceeds 1 million. (Skype 2004) The network effects in IM-like services are more problematic than in the other VoIP classes. The current services are all based on proprietary non-interoperable technologies and protocols, decreasing the end-user value of the services. Each service provider is trying to reach the critical mass and produce the dominant design to the market, but none of them have succeeded so far. Standardized solutions have been developed in IETF on two different tracks, including the recently published set of XML-based Extensible Messaging and Presence Protocols (XMPP, Saint-Andre 2004) and SIPbased solution under development in the SIMPLE working group (IETF 2004). Services conforming to these have not reached any substantial subscriber base yet. For more information on the network effect related market power aspects in the IM market, see Faulhaber (2002). In our view, IM-like VoIP is a low-end disruptive technology, passing the three litmus tests as defined by Christensen & Raynor (2003). Firstly, there exist customers who are willing to use the services even though the technical quality is lower than in the existing PSTN services as a result of non-interoperable services and lack of two-way interconnection to existing networks. Secondly, we believe that it is possible for at least some of the service providers to create business models that allow them to also earn profits even though the IP-to-IP telephony service would remain free. Current models are mostly based on advertising revenues and charging of IP-to-PSTN calls. Peer-to-
14 peer type of IM technologies such as the one used by Skype are also likely to reduce the required investments on centralized server capacity, helping to build sustainable business models. The third and final test requires the innovation to be disruptive to all the significant incumbent firms in the industry. In our view, this is also true, as none of the incumbent telecom operators could consider IM-like VoIP to be a sustaining innovation to their existing services. IM-like VoIP represents a new way of voice communications between people that could be described as a sort of club voice service. The IM systems enable and require users to form club-like groups of friends, relatives, and colleagues, between which the communication takes place using presence information as an aid to forward the calls correctly. Two-way interconnection with public PSTN-like services with global phone numbers is not possible, but the users are willing to accept this as the incentive of free calls is very strong. Only a certain, quite small amount of voice calls are currently able to utilize the IM-like way of communication. In most cases, the call participants have to be subscribed and logged-in to the same IM service, and sit by their home or office PCs equipped with microphones and speakers. Understandably, the network effect related value of such service is quite low. In the near future, however, the users might have WLAN coverage in their homes and offices and IM software running on their WLAN-enabled mobile phones. Full-quality IM-like VoIP services will most probably not be running over mobile networks in the near future because of opposite interests of mobile operators, but there will undoubtedly be room for lower-quality push-to-talk type of VoIP services also in the mobile domain. 5. Service quality and pricing The IP network architecture is driven by the rapid growth of best effort traffic. Due to increasingly high router capacities, decreasingly low latencies, and statistical multiplexing voice calls already now achieve sufficient end-to-end quality in the backbone and broadband access networks in the absence of congestion. In practice, congestion is an issue only in the edge routers, but this is proposed to be solved using local prioritization and access control in favor of delay-sensitive traffic (see e.g. Roberts 2004). The cellular radio spectrum is a scarce resource and more sensitive to IP congestion, but local prioritization is likely to ultimately solve the issue of voice quality also in wireless access. The IP paradigm causes a fundamental change to the voice service architecture by separating the control plane from the user plane. This separation is visible both in the standardized architectures such as SIP, and in the proprietary ones such as Skype. One implication is that the business responsibilities of the voice control servers and the IP transport network are often assigned to
15 different operators. This separation of business responsibility suggests that also the pricing of control and transport will become separate. The operator of the voice control servers will charge subscribers for call control transactions. If the regulator requires strict tracking and storage of call data, the control operator may be able to justify pricing per transaction, although it is simpler to assume flat rate pricing to take place as monthly subscription fees. The IP transport operator, on the other hand, has little reason to separate the pricing of voice traffic from the general IP transport. In the long run, voice is likely to be part of the flat rate or volume-based pricing of the general IP transport. Among other things, this means that distance disappears as a pricing parameter. This new separated pricing structure is emerging first for the aforementioned club voice services, i.e. the IM-like VoIP services not dependent on interoperability with the legacy PSTN voice services. The PSTN-like VoIP service is evolution maintains the interoperability with PSTN, extending it also to pricing mechanisms. For these services, this implies a rather slow evolution toward the new VoIP pricing structure. 6. Conclusions In the paper, we presented possible evolution paths of voice communications, and the role of VoIP services as part of this evolution. Fixed-to-mobile substitution was recognized as the strongest barrier to VoIP evolution. Consumers and business users are increasingly using mobile phones as their only communications devices, decreasing the market potential of VoIP services targeted mainly to the fixed domain. On the other hand, the emergence of WLAN-like technologies in private home and office networks, as well as in multi-mode mobile handsets can increase the potential of VoIP services. In the paper, three different classes of VoIP services were introduced, and their role as part of future voice communications infrastructure analyzed. Whereas the evolution of PBX-like and PSTN-like VoIP classes was found to be sustaining in nature, the IM-like VoIP services represent a more disruptive type of technology evolution. The IM-like VoIP services are still experiencing considerably lower levels of network effects than other voice services, but the argument of WLANs as VoIP service driver applies also here. References Analysys, IP Voice and Associated Convergent Services. Final Report for the European Commission. Contract 02/ January Available at: [Accessed ].
16 Balasubramanian, P.,Kulatilaka, N. and Storck, J. (1999). Managing Information Technology Investments Using a Real-Options Approach, Journal of Strategic Information Systems, Volume 9, Issue 1. Christensen, C.M., The Innovator s Dilemma. New York: HarperBusiness. Christensen, C.M. & Raynor, M.E., The innovator s solution: creating and sustaining successful growth. Boston: Harvard Business School Press. Faulhaber, G., Network effects and merger analysis: instant messaging and the AOL Time Warner case. Telecommunications Policy, 26 (2002), Garcia, R. & Calantone, R., A critical look at technological innovation typology and innovativeness terminology: a literature review. Journal of Product Innovation Management 19 (2002), Internet Engineering Task Force, SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE). Working group web-pages. Available at: [Accessed ]. ITU Recommendation G.114. One Way Transmission Time. February Katz, M. & Shapiro, C., Network externalities, competition and compatibility. American Economic Review, 75(3), MINTC, Mobile services market in Finland Publications of the Ministry of Transport and Communications 24/ Espoo: Edita Publishing Ltd. Open Mobile Alliance, Push to Talk over Cellular Requirements, Version June Reed, D.P., Weapon of math destruction. Context Magazine, Spring Available at: [Accessed ]. Roberts, J., Internet Traffic, QoS and Pricing. Proceedings of the IEEE, Volume 92, Issue 9, September Saint-Andre, P., Ed: Extensible Messaging and Presence Protocol (XMPP): Core. Request for Comments RFC 1738, Internet Engineering Task Force, October Skype Technologies, Company web-site. Available at: [Accessed ]. Statistics Finland, Telecommunications in Finland Helsinki: Statistics Finland. Tikkanen, T., Haikonen, P. & Kääriäinen, M., Future of fixed networks (In Finnish). Publications of the Ministry of Transport and Communications 39/2004. ISBN Espoo: Edita Publishing Ltd. Unlicensed Mobile Access, UMA User Perspective (Stage 1), R1.0.0 ( ). Technical Specification. Vonage, Company web-site. Available at: [accessed ].
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VoIP Glossary Analog audio signals: Analog audio signals are used to transmit voice data over telephone lines. This is done by varying or modulating the frequency of sound waves to accurately reflect the
Voice over IP (VoIP) Basics for IT Technicians VoIP brings a new environment to the network technician that requires expanded knowledge and tools to deploy and troubleshoot IP phones. This paper provides
VoIP Regulation Klaus Nieminen Helsinki University of Technology email@example.com Abstract Voice over IP (VoIP) is currently the uppermost telecommunication regulatory question globally. The purpose
NEWT Managed PBX A Secure VoIP Architecture Providing Carrier Grade Service This document describes the benefits of the NEWT Digital PBX solution with respect to features, hardware partners, architecture,
1.1 Background Voice over Internet Protocol (VoIP) is a technology that allows users to make telephone calls using a broadband Internet connection instead of an analog phone line. VoIP holds great promise
White Paper ON Dual Mode Phone (GSM & Wi-Fi) Author: N Group 1.0 Abstract Dual Mode Handset is in demand for converged Network, Access, Billing, and Operation environment. Dual mode handsets provide cost
MANAGED TELEPHONE AND INTERNET SERVICES Managed Business Solutions Market Brief Insert service provider logo here 2001 Nortel Networks. All Rights Reserved. CONTENTS Introduction...2 Managed Business Solutions...
Whitepaper February 2005 VoIP A Threat and an Opportunity for Mobile Operators A sober analysis of the implications of VoIP on mobile operators business As the trend of All-IP is making its way through
The GENBAND IP Interconnect Solution Natasha Tamaskar VP, Product Marketing GENBAND GENBAND Employees 2,200 Solutions Switching, Networking, and Services Operations 50 Service and Support Centers Market
VoIP and the SMBs - Tapping the Market By Matt Delpercio Despite the benefits of IP telephony, only a small percentage of small to medium businesses (SMBs) use VoIP as their primary means of voice communications.
Digital Video and Picture Communication Prof. S. Sengupta Department of Electronics and Communication Engineering Indian Institute of Technology, Kharagpur Lecture - 39 Video Conferencing: SIP Protocol
Small Logo SIP Trunking: Enabling Wideband Audio for the Dialogic s This white paper is brought to you by Dialogic as part of a continuing series on important communications topics. Dialogic Corporation
Regulation of New Technologies: IP Telephony and Next Generation Networks By Lawrence S M KWAN Seminar on Next Generation Networks and Telecommunication Regulations WuXi, China 25 26 August 2004 1 Outline
Barbados Voice over Internet Protocol (VoIP) Policy Policy in accordance with sections 4 (2)(b) and 4 (2)(f) of the Telecommunications Act Cap 282B. This policy describes the terms and outlines the techniques
PITCOM Voice over Internet Protocol (VoIP) - An Introduction Peter Ingram Chief Technology Officer Ofcom 18th January 2005 Ofcom What is Voice over IP? Carrying Voice Traffic on Networks Designed for Data
Contents 1 Introduction... 2 2 PBX... 3 3 IP PBX... 4 3.1 How It Works... 4 3.2 Functions of IP PBX... 5 3.3 Benefits of IP PBX... 5 4 Evolution of IP PBX... 6 4.1 Fuelling Factors... 6 4.1.1 Demands from
Gateways and Their Roles Understanding Gateways This topic describes the role of voice gateways and their application when connecting VoIP to traditional PSTN and telephony equipment. Analog vs. Digital
Fixed Mobile Convergence Migration for Cable Operators Moving From Next Generation Network to IMS Environment The growing market demand for service convergence is the driving force behind the development
(Voice over IP) Instructor Ai-Chun Pang, firstname.lastname@example.org Office Number: 417, New building of CSIE Textbook Carrier Grade Voice over IP, D. Collins, McGraw-Hill, Second Edition, 2003. Requirements
APPROVAL Date: Description: Analysts In Media Level 9, 55 Broad Street, New York, NY, 10004 T +212 488 1777 F +212 785 2593 IMPORTANT Job#: PLEASE check this proof carefully for errors and omissions. Your
Convergence: The Foundation for Unified Communications Authored by: Anthony Cimorelli, Senior Product Marketing Manager Onofrio Norm Schillaci, Principal Sales Engineer Michelle Soltesz, Director, Marketing
Contact: ALCATEL CRC Antwerpen Fr. Wellesplein 1 B-2018 Antwerpen +32/3/240.8550; Suresh.Leroy@alcatel.be +32/3/240.7830; Guy.Reyniers@alcatel.be Voice over (Vo) was developed at some universities to diminish
Mobility and cellular s Wireless WANs Cellular radio and PCS s Wireless data s Satellite links and s Mobility, etc.- 2 Cellular s First generation: initially debuted in Japan in 1979, analog transmission
VoIP A Threat and an Opportunity for Mobile Operators A sober analysis of the implications of VoIP on mobile operators business As the trend of All-IP is making its way through the telecom industry, new
SIP (Session Initiation Protocol) 1. INTRODUCTION SIP is a text-based protocol, similar to HTTP and SMTP, for initiating interactive communication sessions (voice, video, chat, interactive games and virtual
Reducing your telecommunications costs Research firm IDC 1 has estimated that a VoIP system can reduce telephony-related expenses by 30%. Voice over Internet Protocol (VoIP) has become a viable solution
telephony internet access remote access modems Content Toll-bypass Long Distance Calling... 1 What Is VOIP?... 2 That Was Then... This is Now... Immediate Cost Savings... 3 Applications... 3 Office-to-office
Fax over IP Contents Introduction Why Fax over IP? How Real-time Fax over IP works Implementation with MessagePlus/Open Summary About this document This document describes how Fax over IP works in general
Network support for tele-education Aiko Pras Centre for Telematics and Information Technology University of Twente (UT) http://wwwtios.cs.utwente.nl/~pras This paper discusses the state of the art in networking,
Voice over IP Services Sokos Hotel Vantaa 8.12.2004 Raimo Kantola email@example.com Slide 1 Agenda 1) VOIP motivation 2) VOIP network architecture 3) Operator business challenges 4) Sustainable business
Introduction to IP Telephony In today s competitive marketplace, small businesses need a network infrastructure that will not only save their business money, but also enable them to be more efficient and
IP-PBX for Small to Large Enterprises WHITE PAPER May 2011 Contents Executive Summary Pg.1 IP Telephony An Overview Pg. 2 Matrix IP-PBX solution for Small to Large Enterprises Pg. 4 Benefits of IP-Telephony
SIP trunking, simply put, is a way for you to accomplish something that you already do, for less money, with equal or better quality, and with greater functionality. A Guide to SIP V4 An Introduction to
LTE, WLAN, BLUETOOTHB AND Aditya K. Jagannatham FUTURE Indian Institute of Technology Kanpur Commonwealth of Learning Vancouver 4G LTE LTE (Long Term Evolution) is the 4G wireless cellular standard developed
Title Series Managing IP Centrex & Hosted PBX Services Date July 2004 VoIP Performance Management Contents Introduction... 1 Quality Management & IP Centrex Service... 2 The New VoIP Performance Management
Push-to-talk Over Wireless Is the time right for Push-to-talk? Does it work over GPRS? www.northstream.se Conclusions Push-to-talk is a walkie-talkie-type service implemented over mobile networks. US operator
Internet Protocol (IP)/Intelligent Network (IN) Integration Tutorial Definition Internet telephony switches enable voice calls between the public switched telephone network (PSTN) and Internet protocol
IP Telephony Basics Part of The Technology Overview Series for Small and Medium Businesses What is IP Telephony? IP Telephony uses the Internet Protocol (IP) to transmit voice or FAX traffic over a public
VOIP Security Essentials Jeff Waldron Traditional PSTN PSTN (Public Switched Telephone Network) has been maintained as a closed network, where access is limited to carriers and service providers. Entry
Whitepaper Mobile Enterprise The path to the Mobile Enterprise 1 Executive summary At Ericsson, we are in a unique position to help enterprises achieve a truly mobile way of working. This involves providing
VoIP in the Enterprise Date: March. 2005 Author: Sonia Hanson Version: 1.1 1 1 Background Voice over IP In the late 1990s Voice over IP (VoIP) was seen as a disruptive new technology that had the potential
Voice telephony, the next peer-to-peer application? Georg Schwarz Copyright 2003 Georg Schwarz Table of Contents A technical invention gives birth to a new industry...............................................
IV. Voice Services Current Outlook Voice services on campus and at several off-campus sites are provided by an Aastra MD110 PBX. There are approximately 17,200 campus lines and 1,000 trunk lines. The telephone
Building Voice VPN with Simton IPX (Simton Technologies, Inc.) Version 6 With Simton IPX, the small and medium businesses can easily consolidate data and voice network together to increase productivity,
Fixed-to-Mobile Convergence aus Sicht der Vodafone D2 GmbH Dr. Andreas Jungmaier Network Evolution Strategy and Assessment TNES 22. Treffen der VDE/ITG-Fachgruppe 5.2.4 Darmstadt, 25.01.2007 Contents Types
TAXONOMY OF TELECOM TERMS Prepared by TUFF Ltd This short taxonomy is designed to describe the various terms used in today s telecommunications industry. It is not intended to be all embracing but to describe
White Paper Voice over IP Networks: Ensuring quality through proactive link management Build Smarter Networks Table of Contents 1. Executive summary... 3 2. Overview of the problem... 3 3. Connectivity
ehealth and VoIP Overview Voice over IP (VoIP) configurations can be very complex. Your network could contain a variety of devices, applications, and configuration capabilities to support voice traffic.
Voice Over the Internet Protocol (VoIP) By: Jocelyn Bryant, Wendy Ling, Baan Shubbar and Lena Zahabi Overview What is VoIP? How does it work? Policy History and the CRTC Who are the Players? The Key Characteristics
Allstream Converged IP Telephony SIP Trunking Solution An Allstream White Paper 1 Table of contents Introduction 1 Traditional trunking: a quick overview 1 SIP trunking: a quick overview 1 Why SIP trunking?
CHAPTER 1 Introducing Cisco Unified Communications Express Cisco Unified Communications Express is an award-winning communications solution that is provided with the Cisco Integrated Services Router portfolio.
Written Testimony of John L. Barnes Director of Product Development Verizon Business Hearing on VoIP: Who Has Jurisdiction to Tax It? House Committee on the Judiciary Subcommittee on Commercial and Administrative
Voice Over Internet Protocol (Vo) Issues and Challenges William McCrum Phone: +1 613-990-4493 Fax: +1 613-957-8845 Email: firstname.lastname@example.org Content Network Evolution and drivers Vo Realizations Vo
Voice Over IP Whitepaper, Gareth Senior, CTO, Axiom Systems Voice Over IP: What Lies Beneath January 2003 Introduction to Voice Over IP Voice over IP (VoIP) is the term used for the two-way transmission
Inter-Domain QoS Control Mechanism in IMS based Horizontal Converged Networks Mehdi Mani Wireless Networks and Multimedia Service Department GET-INT Evry, France email@example.com Noel Crespi Wireless
Converged IP Messaging Integrating multiple communications platforms, multiple devices and existing standards for global interoperability Mark Cataldo Chair, OMA Technical Plenary www.openmobilealliance.org
Course Title: Prerequisites: Training Program (5 months) IP Implementation in Private Branch Exchanges Must fresh graduates Communication/Electronics Engineers" 1- Soft Skills Training (4 weeks) 1. Communication
Integrate VoIP with your existing network As organisations increasingly recognise and require the benefits voice over Internet Protocol (VoIP) offers, they stop asking "Why?" and start asking "How?". A
Addressing Convergence and IP Telephony in Enterprise Communications Introduction The convergence of voice and data networks has begun to drive radical changes in the development and delivery of products
SIP Trunking Is a Building Block of Unified Communications by Zeus Kerravala August 2010 Executive Summary Organizations today are undergoing a major transformation to global, Anywhere Enterprises, and
Page 1 of 6 Return to article page To print: Select File and then Print from your browser's menu. This story was printed from FindArticles.com, located at http://www.findarticles.com. America's Network
POZNAN UNIVE RSITY OF TE CHNOLOGY ACADE MIC JOURNALS No 80 Electrical Engineering 2014 Assaid O. SHAROUN* VOICE OVER IP AND NETWORK CONVERGENCE As the IP network was primarily designed to carry data, it
Broadband metrics & Internet service This short paper introduces a definition of Internet service and motivates the adoption of this definition as a precursor to developing standardized measurement methodologies
Emerging Wireless Technologies QCHAT The Future of Push-to-Talk Communications Foreword: The Public Safety Wireless Network (PSWN) Program is conducting an ongoing assessment of advancements in the wireless
Acme Packet session border controllers in the enterprise Large enterprises have been expanding their deployments of IP telephony (IPT) for several years now. Planning has already begun to extend the benefits
Fixed-Mobile Convergence Let s keep it simple Abstract Fixed-Mobile Convergence allows network and service operators to make more efficient use of existing access technologies (GSM, DSL, WiFi), as well
INTERNATIONAL TELECOMMUNICATION UNION ITU-T Y.2001 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2004) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS
FROM TELEPHONY TO COMMUNICATIONS: A NATURAL EVOLUTION REDUCE COSTS AND IMPROVE MOBILITY WITH COMMUNICATIONS APPLICATION NOTE CONTENTS INTRODUCTION / 3 INCREASE PRODUCTIVITY WITH A CONNECTED WORKSTATION
VOIP CONSUMER RETAIL OFFERS VoIP (Voice over Internet Protocol) experienced a first period of hype during the late 1990s but available bandwidth and speech quality were such that faith in VoIP was quickly
International Chamber of Commerce The world business organization Policy Statement Voice over Internet Protocol (VoIP) Prepared by the Commission on E-Business, IT and Telecoms Introduction The emerging
STUDY PAPER on IP PABX (IP based PRIVATE AUTOMATIC BRANCH EXCHANGE) Table of Contents 1. Introduction... 2 2. History & Evolution of PABX... 2 3. The Basic Architecture, its Functions and Interfaces...