Trends in IP Telecommunication

Transcription

1 Trends in IP Telecommunication Dr. Mohammed Khurrum Chairman, Exordium Networks Inc. Nisar Ahmad Touchstone Communications Inc. Abstract The latest trends in telecommunications are VoIP. Within VoIP, SIP has become the defacto standard replacing H323, MGCP, MEGACO and many other proprietary standards. The next wave is Wireless Local Area Networks (WLAN), Wireless Internet Service Providor (WISP), and Wireless broadband (WB). In addition to data, voice will be a major player with voice over WLAN / WISP / WB (VoWLAN, VoWISP, VoWB). Mobility of voice and data is what will be the edge for the service providors and a challenge for 2G and 3G cellular networks. The current technology for wireless data is WiFi and the future seems to be WiMAX. This paper addresses the trends and recommends how a network can use WiFI for Voice and mobility today and have a deployment that will leverage the investment and be ready for WiMAX at the same time. Introduction As the long era of circuit switched telecommunication is coming to a crossroad of the next paradyme shift which came in the form of VoIP, we find ourselves at the infancy of this new era. This is the time when after few initial years of struggle VoIP started to take shape and started being accepted as the new means of communications. Initial fears of QOS, latency, quality, lack of infrastructure etc started to get addressed and VoIP matured. As VoIP became more and more acceptable many protocols started to get dominance. Companies like CISCO who are had big market share in data networks started to push their own propritory protocols and similarly other Telecom giants would push for their propritory protocol or their version of the so called standards. These were again standards that were derived from the Telco ITU standards and not built for the new media which was IP. IETF started the effort to push a new standard that became the most acceptable and now accepted by major telecom corporations as the standard of choice. This is Session Initiation Protocol (SIP). As we have seen this change, VoIP is also going thru another change as IP is changing from wireline to wireless. Voice is also moving towards wireless. Thus the next treand is wireless broadband and then voice over wireless broadband (VoWLAN, VoWB). The big question is how will mobility be addressed in WLANs? And the next trend is the coverage range and availability of thruput. 2G and 3G addressed the issues of mobility and also provided limited data, but at a huge cost. With the introduction of Metro WiFi, and WiMAX ready deployments that are being done now, it s a big challenge for the current 2 and 3G service providors. We will discuss briefly some of the technologies and their applications. We will also point to the trends in VoWB with mobility and recommend in conclusion what service providers should do today; such that they are provide the service today and be ready to leverage their infrastructure when WiMAX comes along. Protocols As SIP[1] has become a defacto standard for voice communication over IP, we will limit ourselves to describing this protocol. Session Initiation Protocol (SIP) is the Internet Engineering Task Force's (IETF's) standard. SIP is an ASCII-based, application-layer control protocol (defined in RFC 2543) that can be used to establish, maintain and terminate calls between two or more end points. SIP is designed to address the functions of signaling and session management within a packet telephony network. SIP has the capabilities to determine the location of the target end point, address 1

2 resolution, name mapping, call redirection, Session Description Protocol (SDP) determine the availability of the target end point, establish a session between the originating and target end point and handle the transfer and termination of calls. SIP uses the multicast and multiple unicast session for conferences between two or more users. SIP is a peer-to-peer protocol. The peers in a session are called User Agents (UAs). A user agent(ua), SIP servers can interact with other application services, such as Lightweight Directory Access Protocol (LDAP) servers, location servers, a database application, or an extensible markup language (XML) application. These application services provide back-end services such as directory, authentication, and billing services. SIP clients include Phones, Softphones, Gateways and SIP server include Proxy server, Redirect server, Registrar server. Users in a SIP network are identified by unique SIP addresses. A SIP address is similar to an e- mail address and is in the format of sip:userid@gateway.com. The user ID can be either a user name or an E.164 address [2]. Technology Standardization being a very important criteria for all new technology, hence service providers have realized a common standard called UMA technology, which defines how Wi-Fi will interoperate seamlessly with traditional cellular networks.unlicensed Mobile Access (UMA) technology enables access to GSM and GPRS mobile services over unlicensed spectrum, including Bluetooth and WiFi. Wi-Fi An abbreviation of Wireless Fidelity, WiFi is take off hi-fi and is considered a generic term that refers to the IEEE communications standards for wireless local area networks(wlans). WiFi entirely new generation technology of portable computers, PDAs, accessing your , accessing web at your home, office, airports, parks, coffee shops, fast food restaurants and thousands of other places where WiFi hot spots are popping up. There are three types of Wi-Fi standards IEEE b, a and g. The advantages and disadvantages of these standards are fairly well published and are not being mentioned here. Wi-Fi Vs Bluetooth Wi-Fi is used now a days in in airports, hotels, hospitals and factories and latter we will see how voice over WiFi is achieved with emphasis on Mobility. Bluetooth offers a world of portable connectivity and connivance and can wirelessly connect the devices together that wouldn t be able to connect to a Wi-Fi network. Bluetooth offers a maximum speed of up to 723 Kbps, more than 15 times slower than b. WiFi Security Standard for wireless security is called WPA (Wi-Fi Protected Access) encryption. WPA is far stronger security protocol that fixes the weaknesses in the previous security standards, WEP (Wired Equivalency Protocol) and adding the software firewall or VPN(Virtual Private Network) can increase the level of security in your computer itself, but still it won t prevent hackers from sniffing your wireless transmissions in the air and getting your private information. [4] Since the introduction of the Wi-Fi Alliance's certification program in March 2000, over 2,000 products have been designated as Wi-Fi CERTIFIED, encouraging the expanded use of Wi-Fi products and services across the consumer and enterprise markets. [5] Wi-Fi vs. cellular Wi-Fi and related consumer technologies hold the key to replacing cellular telephone networks such as GSM. Some obstacles to this happening in the near future are missing roaming and authentication features (SIM cards and RADIUS). These obstacles are being addressed by some companies who are 2

3 providing full mobility voice over wireless broadband (VoWB) solutions. WiMax The term WiMAX comes from 'Wireless (Wi) Microwave Access (MA).' WiMAX is very similar to Wi-Fi in that it uses the same core technology of wireless modulation developed way back in the '60's and '70's. It's called OFDM (Orthogonal Frequency Division Multiplexing), for those that care about the technical terms. The next generation of WiFi, or Wireless networking technology that will connect you to the Internet at faster speeds and from much longer ranges than current wireless technology allows. WiMax Promises the following: Up to a ten (10) mile range without wires Broadband speeds without cable or T1 Handles "last mile" access in remote areas Licencing and equipment due in 2005 Affordable technology [8] In 2009 more than 20 million WiMAX subscriber terminals and base stations will increase per year. The need for inexpensive last mile connections between users and highspeed backbone networks already deployed in the developing world will drive this demand. WiMAX will create a significant opportunity for chip makers. [9] The future of WiMax The WiMax protocol d is used more for promotional purposes. But the implementations among vendors aren t compatible. "There are so many options, and I don t expect companies to give up what they consider their advantage. In addition, d it doesn t satisfy the needs of more mobile users. The "real" WiMax is e, which is fully mobile, Intel which is an investor in Clearwire and also working with Sprint and other carriers on WiMax, has a chip for d and could have an e chip by mid Worldwide interoperability for microwave access (WiMAX) is a broadband wireless access (BWA) technology that does not require line of sight. It can provide Internet at speeds up to 70 Mbps over a distance of 3 to 5 miles under most conditions and up to 30 miles with line of sight, clear conditions and an outdoor mounted antenna. Even at the lower range, WiMAX has a long enough reach and enough bandwidth for hundreds of homes or businesses. Because it does not require line of sight, WiMAX can be a last mile application where trees and buildings pose an obstacle. In addition to providing last-mile access, WiMAX provides excellent backhaul technology to connect wireless local area networks (LANs) and hot spots to the Internet. Hot spots can be established where wired connections are unavailable or prohibitively expensive. Thus, WiMAX could compete with DSL and cable modems for high-speed connectivity and could affect the development of the mobile Internet access market. WiMAX is similar to Wi-Fi in that it establishes a hot spot around an access point that can be used to connect to the Internet, but its range is far greater than the few hundred foot range that characterizes Wi-Fi hot spots. With WiMAX, the configuration would be antennas on a building rooftop or on a tower that transmits signals to subscriber stations. WiMAX will have the advantage of being a standards-based solution from its inception, something that took Wi-Fi several years to achieve. Expectations for today and beyond Expectations for WiMAX infrastructure revenues are expected to grow from $15 million in 2004 to $290 million in The infrastructure revenues include CPE, point-topoint equipment used in backhauling LANs to the Internet and point-to-multipoint equipment used in broadband access. 3

4 Non line of sight ISM Band [13] Fixed-mobile convergence and mobile VoIP will create substantial growth opportunities for mobile voice usage and revenues. The Future of Mobile Voice, projects a $200bn opportunity for additional revenue through the migration of fixed-line traffic to mobile networks. This growth will not automatically go to mobile service providers as new IP technologies allow both mobile and fixed-line operators to compete for market share. To remain on top of mobile voice, mobile providers must rethink their approach to enduser services and networks. Growing mobile voice revenue is an increasingly challenging task. In developed markets, mobile minutes are often given away for a pittance in the heat of competition, decreasing voice ARPS while mobile data adoption remains weak. This makes fixedmobile substitution a major strategy to grow the mobile business. But new IP technologies give fixed-line operators and VoIP service providers a chance to add mobile voice offerings and expand revenue streams. Immediate fixed-line operator strategy focuses on retaining enterprise subscribers through VoWLAN and minimizing fixed-mobile substitution by offering mobile VoIP@Home with UMA technology. Mobile operators must react soon in integrating new delivery networks like WLAN and moving towards mobile VoIP, otherwise they risk losing ground to fixed-line operators, who are aggressively seeking to incorporate mobile services into their portfolios. IP Multimedia Subsystem (IMS) and VoWLAN also allow cellcos to differentiate offerings with personalized mobile voice services, stemming further voice commoditization and strengthening their competitive standing. With 55 million lines and 15% of the voice market, VoIP is an established and rapidly maturing technology. It has been proven to be less expensive to install and maintain the core equipment is comparable in cost to traditional voice, and it offers many more integration options. Wireless technology is also rapidly maturing, so the next obvious step is to deploy a converged technology. Until a few months ago, the converged technology suffered from proprietary equipment, weak security, and a lack of scalable network management tools: It was not quite ready for prime time. All that has changed in the past year. The VoWLAN landscape is rapidly changing with evolving standards, new equipment, and finally some good management tools. Industries where the flexibility, combined voice and data requirements are so compelling that they are willing to forgo the current lack of handset hardware, network management tools and poorly addressed security, standards, and QoS (Quality of Service) issues. Part of the problem is that wireless is a contention media -- the users share the available bandwidth -- so wireless will always have overhead issues and more complex management requirements. Another overlooked issue is how to determine good coverage Industries like Health care and hospitality did transition to VoWLAN because they had widely deployed so they were already comfortable with the technology. The hospitality and retail sectors both have a widely dispersed work force that needs to be in constant communication. Both industries were previously using the 900Mz Walkie-Talkie systems, so conversion to VoWLAN was a natural next step. Beyond those specific industries the penetration has been rather slow because of the perceived security issues and lake of management tools. Recently, there has been a major change in perception as companies discover the benefits of increased flexibility, the improved security standards, and the always popular, substantially lower operational costs. Sophisticated and yet user friendly Wireless Network Management is a critical component to the success of VoWLAN. QoS (Quality of Service) / Reliability 4

5 For data packet delivery, companies are willing to trade mobility and reduced costs for reliability, but voice packets are more sensitive to perceptible service degradation. Cellular has gotten people used to a lower QoS compared to traditional voice, but this will change and people will demand PSTN quality. Wireless Broadband The real benefit of WiMAX technology is that you can run signals very, very close to each other on wireless channels. You can have super narrow lanes, so you can put a lot of traffic over them and they don't disrupt each other. WiMAX v/s Wi-Fi Although the fundamental technology is the same, over time we can add levels of sophistication to WiMAX. Wi-Fi channels occupy a fixed width of the spectrum. But with WiMAX, we're going to enable the traffic lanes or channels to get smaller and narrower. This helps service providers seeking to offer wireless last-mile DSL or cable-type service because they can provide a narrower channel that uses less bandwidth and serve more users. You can take what used to be a fixed Wi-Fi lane and make a bunch more lanes and serve more people. The other big difference between Wi-Fi and WiMAX starting right away is that we're going to use licensed spectrum to deliver WiMAX. To date, all Wi-Fi technology has been delivered in unlicensed spectrum. WiMAX will use one of the unlicensed frequencies, but we're also supporting two other frequencies that are licensed. What that means is that you can turn up the output power and broadcast longer distances. So where Wi- Fi is something that is measured in hundreds of feet, usually WiMAX will have a very good value proposition and bandwidth up to several miles. Those fundamental differences make WiMAX more of a metropolitan area access technology versus hotspot. Hotspot A public Hotspot is a readily available wireless network connection where users with compatible wireless network devices such as PDAs, cell phones, notebook computers, or handheld games can connect to the Internet or private intranet, send and receive , and download files all without being encumbered by Ethernet cables. Metro WiFi Solutions While WiMAX is in development, Metro WiFi fills the gap and prepares the users and the network for WiMAX. This solution allows for full mobility of voice and data without the restrictions of typical 3G or 4G network. Companies like RoamAD whose software is used to manage these networks deploy a infrastructure mesh based cocoon like network that provides many advantages by using the strengths of both designs. RoamAD networks are 'infrastructure-mesh' networks in that they have a traditional infrastructure network for the majority of internetworking communications (in particular for communications to and from the connection point to the Internet), and they employ a mesh architecture on the edge of the network for network nodes, which provide coverage for end users. The following are the advantages of this deployment: 1. Cost effective deployment 2. No requirement for additional customer premis equipment. 3. Radio agnostic software based solution 4. Simple integration with legacy networks 5. Cellular like deployment design 6. Smooth migration and co-existance with WiMAX 5

6 Conclusion In conclusion, we think the trends of telecommunication are moving towards full mobility of voice and data. One should not be tied to a wired LAN to get broadband access and should not have to be stationary while using their phone or their data devices. All features available on a ADSL line should be available wirelessly at an affordable price. It seems RoamAD based Metro WiFI is a good way to go and thus be ready for future developments and deployments like WiMAX. References [1] [2] [3] [4] [5] [6] [7] [8] Strategy Analytics: WiMAX Success in 2009 [9] [10] [11] [12] [13] [14] 6