RAN Gateway wins again

I have spent some time considering the pros and cons of the new 3GPP HNB femtocell architecture. It’s too early to call it a standard, but for now, the basic building blocks are in place for putting the spec together.

One of the fundamental building blocks of the HNB effort is a ‘RAN Gateway’ style architecture. In this case, the RAN gateway network element sits ‘parallel’ to an RNC or BSC, and connects into the mobile core network via existing, well defined circuit interfaces (Iu-CS) and packet interfaces (Iu-PS).

Operators evaluating femtocells and femto architectures immediately grasped the benefits of using a RAN gateway approach:

• All existing circuit and packet services are supported through the femtocell access network as they are supported through the macro RAN network. This is because the RAN gateway uses the same service interfaces as the RNC.
• A ‘RAN’ gateway is located in the RAN, with a clear demark point into the mobile core network. For operators, they did not need to change the MSC or the service core in any dramatic fashion.

For all the rhetoric and posturing around the benefits of SIP and IMS, operators quickly understood that the most pragmatic approach for femtocell service delivery was through a RAN gateway architecture. In fact, one of the things that the proposals from Huawei, NSN, Alcatel/Lucent and Kineto/NEC/Motorola (ie UMA/GAN) all had in common was a RAN gateway.

From a UMA perspective, one important outcome of the HNB specification is a validation of the RAN gateway architecture operators and vendors alike.

UMA/GAN is, of course, the original RAN gateway architecture.

I harken back to the early days of dual-mode handsets (DMH). The debate raged: IMS/SIP/VCC vs UMA/GAN. It’s taken 3 years for this to sort itself out in the market. Today, it’s clear that UMA/GAN and the RAN gateway architecture is the (only?) choice.

In the last 12 months, the debate started again, this time for femtocells. But just as quickly, a winner was declared: RAN gateway for HNB (a la GAN).

VCC?!?! Still??? Really???

VCC, or voice call continuity, seems to still be hanging around in parts of the industry. I must say I continue to be shocked that anyone would even consider it.

First, it must be getting close to done, but for some baffling reason is not completed yet. I think VCC started back in 2005, the same as UMA. If you recall, UMA was actually ratified by the 3GPP in April 2005 (2G) and has since added 3G support, all in the same timeframe that VCC is still languishing.

My position has been and continues to be that VCC is for fixed operators. They have SIP core switches (a VCC requirement) and no direct connection to the mobile service core. I think dual-mode service for fixed operators is a tough sell for many reasons far beyond technology.

Of course, UMA is a 3GPP technology, therefore CDMA networks don’t have an equivalent approach. Some have suggested that these operators may opt for a dual-mode handset/VCC offer, but I think mobile operators in general are too smart to fall for the vendor community’s push on VCC.

VCC offers a different set of services to subscribers when on Wi-Fi than what’s available on the macro network. This is because the handset connects to the SIP core when on Wi-Fi, and to the MSC when on cellular. Different core networks support different services. It’s inconceivable to me that any mobile operator would attempt to roll out a service which didn’t work the same across the entire network.

Frankly the CDMA operators are simply going to do femtocells for their ‘home zone’ service offers. Witness Sprint and Airave. They must have a response to Wi-Fi-based home zone offers like T-Mobile’s HotSpot @Home, and femtocells are a viable alternative.

UMA is the only viable technology for dual-mode services. Period.

Sonus Touts VCC

Vaughn O’Grady, editor of the GSM>3G Vision newsletter, published an interview today with Andy Odgers, vice president of wireless technologies with Sonus. The article is titled “Networks: the VCC version.”

I believe this was in response to an interview Vaughn and I did some weeks back which was (surprise, surprise) very UMA-centric. To be fair and balanced, Vaughn interviewed the ‘other side’, Sonus, who touted VCC as the path to convergence.

As readers of this blog know, I predicted that 2007 was the year that the industry would realize the short comings of VCC and begin to turn against it. UMA is the clear technology choice for mobile operators, whereas fixed operators, who have invested in SIP VoIP switches, are the only operators to potentially benefit from VCC.

Yet VCC has three major short comings:

- There is no data session continuity. As the title clearly states, it’s about VOICE call continuity. Start a streaming data session when on Wi-Fi, walk out the front door, and the session drops. Excellent.

- There is no support for supplemental mobile services. I can’t imagine that SMS wouldn’t be carried forward, but capabilities like MMS, ring tone downloads, over the air updates, or any other mobile application beyond voice is not supported. Again, the name clearly states VOICE CALL continuity, no continuity for anything other than voice calls.

- VCC is still not a standard. I honestly don’t know why this is. UMA went from proposal to the 3GPP in September 2004 to ratification in Release 6 in April 2005. VCC was introduced at least 2 years ago and it’s still not completed.

Perhaps Bridgeport, one of the biggest early VCC supports, was the proverbial canary in the coal mine. They shifted away from dual-mode and VCC more than a year ago. Their industry venture MobileIgnite is, for all intents and purposes, dead. Something is definitely not right in VCC land.

Yet Sonus has recently decided that VCC is the path forward for the mobile network.

I think the misunderstanding about UMA is common for people from the SIP world. He suggests that because networks are moving to IP and that “...as handsets become SIP-enabled – which they are supposed to be in the IMS model, eventually – you’ve solved your [mobility] problem.”

For some reason, simply saying “SIP” immediately implies mobility.

UMA is a RAN technology, akin to 3G. SIP, of course, is NOT a RAN technology. In fact, SIP has no knowledge of the actual transport layer. So why would putting SIP on a handset suddenly make it capable of moving from the 3G network to a Wi-Fi network? It wouldn’t.

In fact, it’s UMA that will keep SIP blissfully unaware of the underlying transport (Wi-Fi, 3G, GSM,...) and free from that complex mobility issue. Put a SIP client on a UMA handset and SIP gets full mobility between networks today, not “...eventually...”.

But I think it’s this comment that really highlights the issue:

“UMA is an interim that has no future; it doesn’t really fit in with an IP core.”

UMA is the structural foundation for mobile operators to use broadband and IP as *the* low cost RAN technology for service delivery in the home and office. It is the future.

Suggesting that a RAN technology like UMA doesn’t fit with an IP core is like suggesting that 3G doesn’t fit with an IP core. It comes down to a lack of understanding.

Sprint likes femtocells - not really a surprise

As reported by Doug Mahoney with VON from a conference in Chicago, Sprint Director of Signaling and Control Technology Manish Mangal stated that the company favored femtocells over Voice over Wi-Fi solutions.

Well, that’s not a surprise at all. For a company like Sprint, the only viable option for voice over Wi-Fi is an approach similar to VCC. As readers of this blog know, I have nothing good to say about VCC.

It’s a train wreck: burdensome to the network, complex t to install, and still not a ratified standard.

VCC isn’t tightly integrated into the phone or network. It’s sort of a ‘loose coupling’ which results in a poor hand-over experience and a high impact on battery performance.

But most of all, VCC delivers a very poor, fragmented user experience. Because subscribers are served from a different core network depending on the RAN they are using, subscriber get different services. How do you explain to someone that their phone can’t download ringtones or send an MMS when on Wi-Fi, but they can when on the CDMA network?

Don't take my word for it, Manish says the same things below:

“We’ve been testing voice over Wi-Fi,” stated Mangal, “There’s lot of hurdles [in implementing it], and no benefits. “There are so many technical issues to make it work.” Problems including the failure of dual-mode devices to catch on in the U.S. “We’ve sold [dual-mode devices], customers aren’t buying them,” he said, deterred by higher price points. Most current wireless networks were deployed as data networks, and haven’t been optimized for voice, so upgrading is expensive. More management time and demands for longer battery life round out the set of problems VoWi-Fi users have listed.

If Sprint’s comments are any indication, our analysis of VCC continues to be dead on. It's funny, operators rolling UMA-based dual-mode services don't have these problems at all.

VCC is (still) for fixed line operators

NXTComm, the former “Supercomm” tradeshow geared towards fixed line operators in the US, wrapped up last week in Chicago. Frankly the VCC world has been pretty quiet of late, but there were three VCC related announcements at NXTComm:

• Aepona is aiming its Voice Call Continuity (VCC) product for service provider OSS and BSS back-office systems integration, offering scalability, service interaction and intelligent rating and charging.

• NewStep Networks and fg microtec, announced that their joint efforts to enable Nokia handsets to interoperate with multimedia applications for 2.5G, 3G and WLAN mobile phones, has led to field trials with major service providers. NewStep also announced that is had completed interoperability certification for Paragon’s latest GSM/VoWLAN dual-mode handset.

• Aricent launched the company’s first VCC server solution, the Aricent Service Continuity Server (SCS).

I guess companies were saving up the news for a fixed-line tradeshow. This just serves to reinforce the message: VCC is a technology for fixed operators.

MobileIGNITE... extinguished?

Launched with much hype and fanfare two years ago, the industry organization which stood for “Integrated Go-to-market Network IP Telephony Experience” seems to have failed to ignite.

It has been awfully quiet from the MobileIGNITE people.

Ironically, the last news item posted on their web site is the announcement of the release 1.0 of the FMC handover specification. This was the pre-cursor to the still pending VCC specification. Having read the document, I can see why things went down hill after that. Granted it was posted on September 27, 2006, but nothing more has been added to the site.

Also ironic is that Bridgeport Networks, a driving force behind MobileIGNITE seems to have abandoned the effort. There is buried a reference to the organization on their site, but it does not appear they are working to keep the flame alive.

As an operator driven initiative from the beginning, UMA continues to gather strength and evolve. Solving real business problems makes industry organizations much easier to sustain.

Telia: UMA and IMS! not really...

When I first saw the headline “TeliaSonera Plans IMS Service in 2008” in Informa's IMS Vision newsletter, I was excited. Telia is a progressive operator and they are investing heavily in their UMA-based dual-mode service called HomeFree. I was certain they were going to combine IMS services onto UMA devices and have seamlessly mobility to Wi-Fi for IMS applications.

Alas, that is not the case. The article interviews Goran Eriksson, TeliaSonera’s head of technology for the broadband/fixed line side of the business.

'The main driver for TeliaSonera to ramp up IMS in the fixed side of the business is to upgrade and enhance its VoIP services and the first ‘IMS service’ that TeliaSonera subscribers will use will be VoIP, in 2008.’

So this is the state of IMS today...

Near the end of the article, it is mentioned that VCC is available from the vendor Telia has chosen for network infrastructure. Mr. Eriksson was coy about any plans. VCC for a fixed operator, what a surprise.

Deutsche Telekom Cancels T-One FMC Service

As reported on Light Reading today, it is certainly a shame that DT cancelled its T-One service (well, not really), I think the announcement warrants a bit “UMA commentary”.

First, as stated, this is a DT (fixed operator) service. Given that dual mode handset (DMH) services are for FMS, it’s always challenging for the fixed operator to reconcile internally a product that fundamentally is about moving minutes off their network.

This is doubly challenging in Germany, as illustrated by the commentary from Current Analysis researcher Emma Morh-McClune, who points out that T-Mobile has a wildly successful FMS cellular home zone” product.

Of course, DT’s service was plagued with all the same challenges of other fixed line operators with DMH services. While there are many other challenges for fixed operators deploying a FMS solution, the fact that T-One only supported a single handset was highlighted as a cause of failure for the service. This is for a couple reasons.

First, the main handset vendors won’t touch the technology until there is some type of standard. The only standard on the horizon for fixed line operators, VCC, still has a ways to go.

Second, fixed line operators really don’t have any pull with the mobile device manufacturers. The cold hard facts are that the vast majority of handsets are sold through the mobile channels. As an operator, if you aren’t moving 10m units or more (I’m guessing) of handsets a year, you don’t have much pull with getting a unique application or service installed on a device.

Such was the case with T-One. This “pre-VCC” solution was based on a non-standard network controller (from Siemens?) and presumably required some heavy pull to get the “special” code loaded onto a single handset from Foxconn. Because the protocol isn’t a standard, it works with that one network controller (Siemens?) and it doesn’t work with Alca-Lu, or Nortel or any other of the other “pre-VCC” vendors.

Even if the standardization/handset availability issues are to be overcome, we haven’t even come to the challenges of providing “mobile services” when the subscriber is indoors and connected to the SIP/VCC controller.

Can the user download a ringtone? Upload an MMS? No.

VCC supports “voice call” continuity, it doesn’t support “MMS” continuity or “Ringtone” continuity or any other application you’re thinking of...

If DT and T-Mobile acted cooperatively rather than competitively, perhaps things would have been different. Arguably it’s a cooperative relationship between BT and Vodafone that has kept the Fusion service going (and the fact that it’s based on UMA, a real standard with real mainstream support).

But I have a feeling this situation is about to be repeated at incumbent providers around the world. The world wants mobile for voice. Investing in fixed line voice services going forward is a losing battle.