The Reality of FMC

2. The Reality of FMC Joe Epstein Meru Networks

3. Caller Mobile Phone What is FMC? • One phone, One number, Multiple Networks • Wi-Fi and Cellular together Wi-Fi Cellular • Strikingly simple concept • But is it really worth it? • Is it easy to deploy? • Does it work?

4. The Power of FMC • Reachability • Users can be reached anywhere • Indoors or outdoors • In the office or on the road • Productivity • No worries about flight delays, travel delays, missed connections • Enhances Workforce Mobility • Address-free mobility • Work from any office—goes with you. • Cost savings • Reduced initial costs • One device per person: no need for desk phone or wiring • Reduced operating costs • Office indoor calls are free (or reduced)

5. The Choices… • You have to choose • Who owns the phone number? • The cellular carrier or • You • Do you care about seamless handoff? • Or is everywhere reachability enough by itself? • Do you want to bring in new vendors just for FMC? • Your choice picks • The technology • The features • Whether you’re locked in to a solution

6. Case Study: An FMC Winner • Osaka Gas • Japan’s second largest utility company • Completely unwired office • 11,000 office desk phones reduced to 4,000 conference room phones, hall phones, and backups • 4,000 existing wireless extensions converted to FMC • Address-free hotelling environment • Estimated savings per year $4 million

7. Carrier-based FMC • The carrier owns the number (650) xxx-xxxx Carrier’s Network Caller Internet Enterprise Border Wi-Fi Hotspot Cellular Enterprise Wi-Fi • The technology • Today, UMA • The carrier sees the enterprise as nothing more than a big hot-spot

8. Carrier-based FMC (2) • IP becomes an extension of the carrier • Cellular signaling and voice packets get wrapped in UMA tunnel • These opaque packets get tunneled through the enterprise, to the phone • Why might carriers like this model? • Works across any IP-based network • Easier for them to deploy • Enables carrier to charge for every call • Easy to abstract out the part that’s the most variable • The enterprise

9. Features of Carrier-based FMC • True one-phone number system • But number is outside the enterprise • Uses a typical cell number • Abbreviated (5 digit) dialing available only if software is configured to fill in the missing digits • No integration with enterprise call systems • All calls are still outside of the enterprise, coming in—even office to office • Complexity is partially taken care of by the carrier or handset manufacturer • UMA phones already exist—no special software needed • Presumably no tuning needed • Not true in practice

10. Other side of Carrier-based FMC • Really designed for the home market first • Coverage extension for out-of-range consumers first • Possibly will lighten load on carrier’s networks • Limitations • Requires the enterprise to open a hole in the firewall for UMA • Questions arise about enterprise and guest user segregation • Strongly decreased visibility into the health of the network • Intra-office calls must go through carrier’s network • Same as a normal carrier voice call • Reduced cost savings: carriers may still charge for every call • Extremely Limited Availability • UMA is available on some phone models today • One US carrier is in small trials, for the home market • Other carriers are looking past UMA to IMS

11. Enterprise-based FMC • The enterprise owns the number (408) 555-xxxx (650) xxx-xxxx Carrier’s Network Enterprise IP PBX Caller FMC Gateway Enterprise Wi-Fi Cellular FMC Software • The technology • Handset software + Enhanced PBX or added FMC Gateway • The enterprise sees the carrier as nothing but an external phone line

12. Enterprise-based FMC (2) Calling (408) 555-xxxx • Hairpinning Carrier’s Network Enterprise IP PBX Caller Calling (650) xxx-xxxx FMC Gateway Enterprise Wi-Fi Cellular • Phone roams outside of Wi-Fi network • The FMC Gateway registers on behalf of the phone to the PBX • The FMC Gateway creates new outbound call to the phone’s real number and bridges the calls

13. Enterprise-based FMC (3) • FMC software on handset • Adds another, new phone application to the handset • Integrates with address book, to varying degrees • User must remember to use this application, and not the phone application that comes with the handset • Connects to FMC Gateway either through the WLAN or Internet • Provides PBX access when roaming • Provides 5-digit dialing • Controls the Wi-Fi (SIP) and cellular endpoints in the phone • Performs the seamless handover

14. Advantages of Enterprise-based FMC • Enterprise owns the phone number • Phone becomes a PBX extension, inside and out • PBX features are usually available • Reduced cost calling • All internal calls run over the wireless LAN, when phone is in the office • All external calls run over the PSTN, which is generally cheaper than cellular • Abstracts out the carrier • The largest unknown in the system, from an enterprise point of view • Possibly easier to switch carriers

15. Who Provides Enterprise-based FMC • PBX + Handset Partnerships • Example • Avaya/Nokia, with Avaya’s one-X software preloaded on phone • Works with Avaya IP PBX • Full PBX integration • Higher degree of phone integration • Limited to the PBX and phone vendor • Startups and independent companies • Requires FMC Gateway independent of PBX • FMC Gateway may use PBX APIs • Or may be fully independent and use SIP • Also requires custom phone software • Varying degrees of integration with the phone

16. The Other Side of Enterprise-based FMC • Occupies more enterprise telephony resources • Incoming calls to roaming phones must take up two lines and two ports on the PBX • Outgoing calls from roaming phones may also share this problem • Many solutions are early • A number of them are in prototypes or beta • Many are not widely deployed • Technical issues may restrict to a subset of the already small set of dual-mode phones

17. The Critical Pieces

18. Voice over Wi-Fi • This is the biggest variable in all types of FMC • Forces enterprises to become “carriers” to their employees • Must provide toll-quality voice service levels to phones • Requires “SLA” thinking • Must monitor for outages or poor quality • In general, requires a much higher degree of sophistication about the wireless network • Without strong Voice over Wi-Fi service, the system collapses back into cellular-only

19. Why Strong Coverage is Crucial • The handset has to choose which network to pick • Which one is currently better: Wi-Fi, or cellular? • Each change is expensive • If no seamless handoff is supported, then the call is dropped • Seamless handoff may still have seams—sometimes around 2 seconds • Using cellular when the phone is indoors costs money • Handsets choose Wi-Fi when they can associate with high signal strength • Low signal strength or packet loss can signal to the handset to switch back to cellular, even when no call is in place • Even small coverage holes within the enterprise can, thus, trigger handover

20. Why Wi-Fi Handoffs Hurt • Well-designed deployments have coverage everywhere • Usually one access point provides good signal at every location • However, phones have to change channels during Wi-Fi to Wi-Fi handoff • 3 channels on 11bg • 20 channels on 11a • Phones have to scan • Phones stop transmitting, change channels briefly, and check for a new access point • This either disrupts the call or takes a very long time to complete • Handoffs may fail • Long delays in handoff may cause the phone to lose its old AP • This loss may trigger the phone to roam to cellular

21. How Voice Quality is Measured • 4.0 – 5.0: Toll quality • 3.5 – 4.0: Usable but dissatisfying, cellular quality or worse • 3.0 – 3.5: Nearly unusable • 1.0 – 3.0: Not recognizable • Mean Opinion Score (MOS) • Goes from 1 to 5 • Originally measured by humansurveys • R-Value • 100-point scale • Maps directly to MOS and back • E-Model • ITU G.107 model for predicting voice quality based measurable factors • Fit into packet-based systems to provide quality on the basis of jitter, delay, and loss • PESQ • ITU P.862 method for measuring voice quality based on real samples • Better for measuring analog systems and the behaviorof new codecs • 80 – 100: Toll quality • 70 – 80: Usable but dissatisfying, cellular quality or worse • 60 – 70: Nearly unusable • 0 – 60: Not recognizable

22. Why Toll-Quality Voice is Crucial • Several factors to poor voice quality • Not just poor coverage • Density, Resource Starvation, Contention, Interference • Handsets can’t detect these parameters well • Usually need to have an active call ongoing on Wi-Fi to measure these • Thus, handsets may end up sticking to a bad Wi-Fi network • Users complain loudly • The system doesn’t work

23. Why Data is Crucial • Except in rare circumstances, most Wi-Fi networks are data networks • It may be hard to justify a voice-only network • Even if data density is low, voice and data must not interfere with each other • On some systems, data will degrade voice, especially when voice is at scale • On other systems, voice will severely degrade data • WMM, by itself, is not enough • Quality-of-service must recognize voice calls specifically

24. What to Look For in Wi-Fi • Toll-quality voice, Always • Admission control, when resources are overtaxed • Caller must get busy tone • Strong coverage with no Wi-Fi handoff glitches • Stacked single-channel deployments eliminate scanning and handoff • High density support for voice • Phone users tend to congregate • Voice and data must not interfere • Assured levels of quality of service, not just differentiation of packet types

25. Predictions & Hopes • UMA will fade out of consideration for enterprises • Handset and OS manufacturers may take over FMC phone software • Expect to see APIs • An interoperability industry may or should form • Technologies, such as 802.11u/802.21, may influence this • Both PBX and independent models will remain • Different enterprise users will favor different models

26. Conclusions • FMC is Reality, outside of USA • Slow adoption in the US • FMC is coming to USA, look for more deployments in 08 • Exists everywhere else, outside of US • The technology exists • Handset choices may be limited for a while here, compared to overseas • Seamless handoff is still difficult • But mobility is available and solid • The models are still in flux • Natural tension between carrier and enterprise-based models