The compelling selling points of femtocells are increasingly becoming more noticeable.
The apparent strong compelling factor is the disruptive value proposition in terms of cost of delivering a minute of calls (or Mbytes of data) to the end user. Another obvious one is related to service bundling and other innovative marketing ideas.
One area that is increasingly getting attention is the femtocell as platform for added value services (VAS) . The femtocell concept can be extended to make it an integrated 3G access point and intelligent home gateway that offers added value services to the customer. Imagine what can be achieved if a mobile operator can offer something like this, but with a proper cellular flavored radio. This will make femtocells ideal candidates for IMS type of deployments.
The femtoell can also be used as a content distribution platform. In this model content/services/application can be pushed to the UE when the femtocell senses the UE is in its vicinity.
Even a more exciting proposition, is what I call Reverse Content Distribution, where a roaming user outside the femtocell zone can access his content remotely. The femto can orchestrate the user’s access to various equipments at home, such as the PC, Home Media Server, Apple TV, …etc. It can also perform various remote home control functions, like switch on the heating, prepare the bath, access the burglar alarm …etc. There are various mechanisms to enable this. For example, it can be via a femto access interface on the application level. Alternatively, the femtocell can be a passive element and home control can be achieved pretty much in the same way it can be done today from a PC across the internet.
Showing posts with label IMS. Show all posts
Showing posts with label IMS. Show all posts
19 Oct 2007
6 Jul 2007
Sonus and the Femtocell backhaul integration with core.
There are as many companies active on the femtocell backhaul integration with IP core as there are Femto cell manufacturers, with Kineto, Sonus and Tatara systems topping the list.
Sonus has recently announced partnerships with three femtocell manufacturers: ip.access, 3way and RadioFrame.
My worry is that some companies in the IP core space are re-inventing the wheel so to speak which threatens the main selling story for femtocells: the low introduction cost and the potential savings to operators. I'm no core expert, but I would guess that the existing framework(s) are sufficient to enable Femtocell integration with core networks without any major investment or development effort.
Sonus has recently announced partnerships with three femtocell manufacturers: ip.access, 3way and RadioFrame.
My worry is that some companies in the IP core space are re-inventing the wheel so to speak which threatens the main selling story for femtocells: the low introduction cost and the potential savings to operators. I'm no core expert, but I would guess that the existing framework(s) are sufficient to enable Femtocell integration with core networks without any major investment or development effort.
20 Jun 2007
Femtocell Challenges
In a previous post I talked about the potential benefits of femtocells to the operators as well as consumers. In this post I'd like to investigate the potential hurdles in the road to viable femtocell solutions.
Looking at various analysts remarks I narrowed the list of potential show stoppers to the following items, all of which are not unresolvable, but one has to be aware of:
Cost:
This is the obvious one. There is no doubt that we are well into the cost reduction era. This is by far the number one item on every operator's agenda. The bottom line is that operators want to see a nice dollar savings associated with Femto cells, which increases pressure on femto cell development firms to reduce their price tag. Traditionally, pricing is based on a BOM plus margins. An alternative way for development firms is to price based on potential benefits/savings. My firm has recently been engaged in a similar pricing activity with a potential investor.
The cost challange means that there is a limit to the amount of effort and features developers will bundle in the femto cell box. Deciding what is "sufficient" feature list is a difficult call (check the technology life cycle model proposed by D. Normann in one of my previous posts)
Radio Planning and interference management:
Unlike Wi Fi, the Femto cell is likely to use the licensed spectrum e.g. UMTS band. Although it is my view that the femto network is better have its own carrier, many clients would like the femto cell concept to work on the same carrier frequency used by existing infrastructure be it a macro, micro or pico layer.
Femtocells are expected to coexist with the rest of the network by automatically configuring themselves. Operator or user intervention is undesirable...a femto cell box has to be fully plug and play without the need to setup,configure or optimise it in anyway. Therefore lots of effort is being spent on femto cell radio management features e.g. choosing the right carrier, automatic setting of power levels, protecting other infrastructure from harmful interference, handoff ...etc .
Core Network Integration:
I touched upon this in a previous post (Femtocell Architecture).
In a nutshell, a legacy architecture is too old fashioned, while on the other hand a full flat IP architecture with an IMS core is an expensive undertaking with no sign of becoming available soon.
Interim solutions relying on some kind of concentrator seem to attract some attention. I can't really comment much on this and I'll leave it to the core experts to make their minds.
With converged solutions such as femto cells there is also an increased expectation of a higher level of network intelligence and features at the edges of the network (as opposed to the traditional model of core intelligence).
End user perception:
The consumer will (and has to) ask: "what's in it for me". At the moment most of the promises revolve around cheaper calls as well as using the often over hyped word: "convergence". The fact is that most people do not know what this word means! The operators will find it challenging to convince the consumer that the femtocell is the way to go.
In addition, there is the issue of backward compatibility in terms of usage. Many people have Internet access at home and a big proportion use WiFi routers to have wireless coverage at home. Is the Femtocell going to replace that? if so, then there is a need to have a combined WiFi/Femto router to enable legacy equipment to access the Internet. Alternatively people will end up with a stack of routers, from different suppliers.... hardly a convergent solution!.
Therefore the extent of device convergence will play a significant role in any operator's femtocell strategy.
There are also health concerns about exposure to increased levels of RF waves.
Looking at various analysts remarks I narrowed the list of potential show stoppers to the following items, all of which are not unresolvable, but one has to be aware of:
Cost:
This is the obvious one. There is no doubt that we are well into the cost reduction era. This is by far the number one item on every operator's agenda. The bottom line is that operators want to see a nice dollar savings associated with Femto cells, which increases pressure on femto cell development firms to reduce their price tag. Traditionally, pricing is based on a BOM plus margins. An alternative way for development firms is to price based on potential benefits/savings. My firm has recently been engaged in a similar pricing activity with a potential investor.
The cost challange means that there is a limit to the amount of effort and features developers will bundle in the femto cell box. Deciding what is "sufficient" feature list is a difficult call (check the technology life cycle model proposed by D. Normann in one of my previous posts)
Radio Planning and interference management:
Unlike Wi Fi, the Femto cell is likely to use the licensed spectrum e.g. UMTS band. Although it is my view that the femto network is better have its own carrier, many clients would like the femto cell concept to work on the same carrier frequency used by existing infrastructure be it a macro, micro or pico layer.
Femtocells are expected to coexist with the rest of the network by automatically configuring themselves. Operator or user intervention is undesirable...a femto cell box has to be fully plug and play without the need to setup,configure or optimise it in anyway. Therefore lots of effort is being spent on femto cell radio management features e.g. choosing the right carrier, automatic setting of power levels, protecting other infrastructure from harmful interference, handoff ...etc .
Core Network Integration:
I touched upon this in a previous post (Femtocell Architecture).
In a nutshell, a legacy architecture is too old fashioned, while on the other hand a full flat IP architecture with an IMS core is an expensive undertaking with no sign of becoming available soon.
Interim solutions relying on some kind of concentrator seem to attract some attention. I can't really comment much on this and I'll leave it to the core experts to make their minds.
With converged solutions such as femto cells there is also an increased expectation of a higher level of network intelligence and features at the edges of the network (as opposed to the traditional model of core intelligence).
End user perception:
The consumer will (and has to) ask: "what's in it for me". At the moment most of the promises revolve around cheaper calls as well as using the often over hyped word: "convergence". The fact is that most people do not know what this word means! The operators will find it challenging to convince the consumer that the femtocell is the way to go.
In addition, there is the issue of backward compatibility in terms of usage. Many people have Internet access at home and a big proportion use WiFi routers to have wireless coverage at home. Is the Femtocell going to replace that? if so, then there is a need to have a combined WiFi/Femto router to enable legacy equipment to access the Internet. Alternatively people will end up with a stack of routers, from different suppliers.... hardly a convergent solution!.
Therefore the extent of device convergence will play a significant role in any operator's femtocell strategy.
There are also health concerns about exposure to increased levels of RF waves.
13 Jun 2007
Femto cell Architecture
The business case for indoor femto cells has gained increasing traction in the last few weeks, and lots of news comments about various femto cell development companies. For example, check here, here and here.
Although the femto cell concept is quickly gaining grounds towards complete and operational products, there is still some misunderstanding on how the overall network architecture will look like. I'll try to address this issue in this post.
A femto cell router is a small device, the size of any Wi-Fi router, which is in effect a miniature base station. The radio is a standard based radio such as UMTS/HSPA which the operator will likely require a license to operate on. The router connects to a DSL line. The idea is to enable the subscriber to make and receive mobile calls indoors, with low signal levels which has a number of benefits to the operator:
- Hopefully accelerate fixed line substitution.
- Reduce the cost of building a full macro layer network.
- Lock subscriber in to the operator and reduce the likelihood of churn.
- Provide a viable medium for content distribution (the ugly walled garden paradigm)
It is not my intention here to argue for or against these benefits. I will dedicate a full post on the business case for the femto cell and the potential cons sometime soon. So let us stay on the technology side and try to investigate how a UMTS based femto cell routers will be integrated with the operator's core network.
Basically, there are a number of ways, the first of which is the conventional hierarchy using an RNC . Just like any node-b is connected back to an RNC which is then in turn is connected to the core network, the femtocell routers can be treated like individual node-bs and connect to RNCs. This may appeal to big manufacturers who already have substantial deployments and many RNC on the ground. The downside to this approach is the limited chances of inter-operable devices if the operators chooses to diversify their suppliers. Although the Iub interface (base station to RNC) is standardised, the reality is most implementations are proprietary. Typically operators don't like to put all their eggs in one basket and would prefer to get solutions from various suppliers. The other downside of this approach is that most available RNC solutions are geared towards Macro/Micro type of deployments. In other words they are built in order to support relatively small number of cells with a huge number of subscribers in each cell. They don't scale very well to support Femto cell deployments with almost as many cells as there are subscribers, and a handful of subscribers per cell.
An alternative approach is to use UMA (or now called GAN). UMA was originally conceived to support dual mode cellular/WiFi-over-Internet type of connectivity. When the mobile is detected indoors within the range of pre-determined WiFi coverage, a UMA concentrator does the core network negotiation on behalf of the mobile, e.g. registering, and updating location ... etc. It is thought that a similar procedure can be used for femto cells. When the mobile is detected within the coverage of a femto cell, UMA kind of hand shaking takes place to ensure that: 1. the mobile is allowed to access the network at this particular femto cell, 2. the traffic between the mobile and the core network is forwarded accordingly. Using this method a UMA concentrator is required, so in a way, the solution is still hierarchical and it is certainly one of the criticisms of this method is that it is not a fully flat architecture. Kineto is one of the companies promoting this approach.
Yet another alternative approach is enabling femto cell connectivity through an IMS service. In this approach, the femto cell router talks SIP over the internet back to an IMS service which acts as a bridge between the femto layer and the rest of the network. Although this is considered the "flattest" approach, it is yet to understand how it will work in practice, the delay in working fully featured IMS platforms is one of the concerns of femto cell development companies.
Incidentally, my current clients are hedging their bets by supporting more than one approach and have developed partnerships with various companies in their respective fields to make the Femto architecture as flexible as possible.
Although the femto cell concept is quickly gaining grounds towards complete and operational products, there is still some misunderstanding on how the overall network architecture will look like. I'll try to address this issue in this post.
A femto cell router is a small device, the size of any Wi-Fi router, which is in effect a miniature base station. The radio is a standard based radio such as UMTS/HSPA which the operator will likely require a license to operate on. The router connects to a DSL line. The idea is to enable the subscriber to make and receive mobile calls indoors, with low signal levels which has a number of benefits to the operator:
- Hopefully accelerate fixed line substitution.
- Reduce the cost of building a full macro layer network.
- Lock subscriber in to the operator and reduce the likelihood of churn.
- Provide a viable medium for content distribution (the ugly walled garden paradigm)
It is not my intention here to argue for or against these benefits. I will dedicate a full post on the business case for the femto cell and the potential cons sometime soon. So let us stay on the technology side and try to investigate how a UMTS based femto cell routers will be integrated with the operator's core network.
Basically, there are a number of ways, the first of which is the conventional hierarchy using an RNC . Just like any node-b is connected back to an RNC which is then in turn is connected to the core network, the femtocell routers can be treated like individual node-bs and connect to RNCs. This may appeal to big manufacturers who already have substantial deployments and many RNC on the ground. The downside to this approach is the limited chances of inter-operable devices if the operators chooses to diversify their suppliers. Although the Iub interface (base station to RNC) is standardised, the reality is most implementations are proprietary. Typically operators don't like to put all their eggs in one basket and would prefer to get solutions from various suppliers. The other downside of this approach is that most available RNC solutions are geared towards Macro/Micro type of deployments. In other words they are built in order to support relatively small number of cells with a huge number of subscribers in each cell. They don't scale very well to support Femto cell deployments with almost as many cells as there are subscribers, and a handful of subscribers per cell.
An alternative approach is to use UMA (or now called GAN). UMA was originally conceived to support dual mode cellular/WiFi-over-Internet type of connectivity. When the mobile is detected indoors within the range of pre-determined WiFi coverage, a UMA concentrator does the core network negotiation on behalf of the mobile, e.g. registering, and updating location ... etc. It is thought that a similar procedure can be used for femto cells. When the mobile is detected within the coverage of a femto cell, UMA kind of hand shaking takes place to ensure that: 1. the mobile is allowed to access the network at this particular femto cell, 2. the traffic between the mobile and the core network is forwarded accordingly. Using this method a UMA concentrator is required, so in a way, the solution is still hierarchical and it is certainly one of the criticisms of this method is that it is not a fully flat architecture. Kineto is one of the companies promoting this approach.
Yet another alternative approach is enabling femto cell connectivity through an IMS service. In this approach, the femto cell router talks SIP over the internet back to an IMS service which acts as a bridge between the femto layer and the rest of the network. Although this is considered the "flattest" approach, it is yet to understand how it will work in practice, the delay in working fully featured IMS platforms is one of the concerns of femto cell development companies.
Incidentally, my current clients are hedging their bets by supporting more than one approach and have developed partnerships with various companies in their respective fields to make the Femto architecture as flexible as possible.
18 Dec 2006
VoIP over UMTS: The Finale - Embrace the trend or block the threat?
This post is a try to summarise and distill a theme from the previous posts about VoIP over UMTS, without getting much into the technical detail, but rather by proposing a view of the telecomm market and motivations for VoIP.
First, let us get the definitions out of the way:
VoIP over cellular:
Carry the voice conversations of mobile users using VoIP by routing them over a packet-switched network, instead of the traditional dedicated, circuit-switched voice transmission lines.
The Market landscape:
Fixed Line broadband prices are falling. Fixed operators offer a huge bandwidth at cheap prices. With a WiFi extension it is possible to become semi-mobile. Fixed line operators realised that they have to diversify their business instead of relegating themselves to become ISPs and ISP carriers. Therefore came up with the Fixed-mobile Convergence concept. They want to win part of the mobility market by putting together compelling UMA offerings. Mobile operators undoubtedly will fight back, probably with home/enterprise collapsed architecture base stations.
Mobile operators see DSL as a headache, because suddenly they have to compete to offer high throughput. They have been fighting an uphill battle with WiFi (and soon WiMax) since they shifted their focus to “high throughput”. Mobile operators are generally unimaginative and still think in terms of “talk”, “text” and recently “broadband”, instead of capitalising on their greatest assets: mobility and location information.
The Proliferation of Wireless broadband has changed the mobility landscape. There are WiFi hotspots on every corner. WiFi Social networks are emerging. (FON): a company that gives you a customised router and allows you to share your broadband with other FONers. Businesses can also make money.
From the regulatory point of view, there is an increasing pressure on reducing mobile roaming charges. Also, it is still ambiguous how mobile data termination charges will be collected, at the moment there aren’t any, which makes VoIP an appealing solution.
Advent of “convergence” has put vendors in a predicament. Now they are trying to sell “standardised” architecture to very different types of customers.
Whenever the industry gets excited about new technology, financial institutions and banks become skeptical because they want to see some ROI on existing investments before committing any new ones.
If they don't embrace VoIP, mobile operators face a threat from it. Enterprise VoIP is already perceived to be a major threat. At the moment they are resist the trend and offering differentiated services to their enterprise customers, e.g. extension dialling
Shift in Markets structure:
The industry is moving away from a vertically integrated arrangement, where operators (think vodafone) own the infrastructure, the frequency, the transport, and applications, the portals, the content and the handsets. The future will be different, companies will own infrastructure to carry multiple types of traffic and a myriad of access technologies (fixed +wireless). Other companies will specialise in content provisioning, others will concentrate on marketing and user acquisitions.
It will be interesting to see how incumbents will shift away from current business models. There is space to diversify revenue streams: For instance, new technology will enable operators to challenge traditional promotion channels. Location information is a great asset and many interesting applications can be wrapped around it.
At the end of the day social re-engineering can open up new business models and allow the industry to get into new businesses. For example, adopting “work from home” ethos will allow telcos to compete with many industries such as: Real estate, car industry, and transportation service providers!.
VoIP over UMTS: motivation and market drivers:
First, let us get the definitions out of the way:
VoIP over cellular:
Carry the voice conversations of mobile users using VoIP by routing them over a packet-switched network, instead of the traditional dedicated, circuit-switched voice transmission lines.
The Market landscape:
Fixed Line broadband prices are falling. Fixed operators offer a huge bandwidth at cheap prices. With a WiFi extension it is possible to become semi-mobile. Fixed line operators realised that they have to diversify their business instead of relegating themselves to become ISPs and ISP carriers. Therefore came up with the Fixed-mobile Convergence concept. They want to win part of the mobility market by putting together compelling UMA offerings. Mobile operators undoubtedly will fight back, probably with home/enterprise collapsed architecture base stations.
Mobile operators see DSL as a headache, because suddenly they have to compete to offer high throughput. They have been fighting an uphill battle with WiFi (and soon WiMax) since they shifted their focus to “high throughput”. Mobile operators are generally unimaginative and still think in terms of “talk”, “text” and recently “broadband”, instead of capitalising on their greatest assets: mobility and location information.
The Proliferation of Wireless broadband has changed the mobility landscape. There are WiFi hotspots on every corner. WiFi Social networks are emerging. (FON): a company that gives you a customised router and allows you to share your broadband with other FONers. Businesses can also make money.
From the regulatory point of view, there is an increasing pressure on reducing mobile roaming charges. Also, it is still ambiguous how mobile data termination charges will be collected, at the moment there aren’t any, which makes VoIP an appealing solution.
Advent of “convergence” has put vendors in a predicament. Now they are trying to sell “standardised” architecture to very different types of customers.
Whenever the industry gets excited about new technology, financial institutions and banks become skeptical because they want to see some ROI on existing investments before committing any new ones.
If they don't embrace VoIP, mobile operators face a threat from it. Enterprise VoIP is already perceived to be a major threat. At the moment they are resist the trend and offering differentiated services to their enterprise customers, e.g. extension dialling
Shift in Markets structure:
The industry is moving away from a vertically integrated arrangement, where operators (think vodafone) own the infrastructure, the frequency, the transport, and applications, the portals, the content and the handsets. The future will be different, companies will own infrastructure to carry multiple types of traffic and a myriad of access technologies (fixed +wireless). Other companies will specialise in content provisioning, others will concentrate on marketing and user acquisitions.
It will be interesting to see how incumbents will shift away from current business models. There is space to diversify revenue streams: For instance, new technology will enable operators to challenge traditional promotion channels. Location information is a great asset and many interesting applications can be wrapped around it.
At the end of the day social re-engineering can open up new business models and allow the industry to get into new businesses. For example, adopting “work from home” ethos will allow telcos to compete with many industries such as: Real estate, car industry, and transportation service providers!.
VoIP over UMTS: motivation and market drivers:
- There is a big hype behind VoIP over cellular, largely because of the attention it attracts in fixed networks and internet world.
- There is a perception that VoIP over cellular will be cheap. This may be true if the operator already has an under-utilized packet core network for example. Nevertheless, offering operator controlled VoIP is not necessarily cheap. Having to run an IMS network to control VoIP introduce what is called “IMS Tax”, where the mobile operator has to deal with increased traffic for the same number of calls, and loose one of their greatest advantages: the ability to carry CS voice efficiently.
- There is also a view that VoIP over cellular is inevitable because once LTE is out CS voice is dead.
- If an operator wants to deploy IMS capabilities, VoIP can be bundled with other added value services and experiences, which hopefully will make a good compelling offer.
- There is a perception that VoIP offers some advantages in terms of capacity , quality and efficiency.
- Convergence: “VoIP fits well with the all IP convergence concept”. The fact of the matter is that convergence is not exactly “all IP”. Convergence is : "the process of replacing several legacy networks (boxes) based on old technology with a single network for all telecomm services, and for all telecom access (fixed + wireless)". So the theme is: a simplified, scalable and integrated transmission and core network.
What is the right VoIP over UMTS operator strategy?
There are two generic strategies which are opposite to each other, and a spectrum of possibilities in between. Essentially, the operator can either offer VoIP is a cheap substitute of voice calls, with limited investment in infrastructure and very much in line with the traditional internet provisioning model, or alternatively, offer a differentiated and high quality voice which is part of a more compelling and complete offering.
Cheap:
- The Premise: Subscribers want to do cheap voice calls.
- Provider mentality: “We give the pipe, you do the skype”.
- Follows the broadband ISP model by providing access to the internet and no additional differentiated services.
- Best effort voice calls.
- User experience is not seamless: standalone applications for VoIP and users have to know how use them.
- Ubiquity to the internet user, who can access their VoIP provider accounts from any terminal using any type of access. (unless blocked by a scrupulous operator).
Premium:
- Premise: Subscribers want to do reliable voice calls.
- Walled Garden mentality: “My network, my revenue”. Operator wants to charge for your VoIP calls.
- Guaranteed quality.
- Seamless user experience: user does not know his calls are carried over VoIP
- User ubiquity undermined by walled garden, perhaps have to pay for ubiquity.
- Differentiate the voice offering by value added services. VoIP becomes part of a complete compelling offer. (not voice centric).
Conclusion:
On the long term, VoIP over cellular is inevitable. However, there are serious issues to be addressed by the cellular mobile operators if they want to still exist few years down the line. They have to make up their mind what business they want to be in, and have to adapt to the new world of horizontal integration. It is very likely that the term "mobile operator" will diminish or disappear with new revenue streaming and business models emerging.
Contact me to get a power point presentation slides on VoIP over UMTS strategy)
3 Dec 2006
Review of article: What exactly is IMS?
Just read this article by Ian Poole in IET Communications, which is a good overview of IMS architecture. (I don't know why I pay them subscription fees for the magazine when you can download all the articles for free!).
I am not convinced that the need for IMS stems from the desire to "converge". The main objective for IMS is to give the operators a mechanism by which they can charge for any user activity and control the content distributed over their network. With the introduction of 3G data access the operators realised that the future is bleak if they simply offered mobile data speeds for users to access the (mostly) free Internet content. Therefore they wanted a mechanism by which they offer an alternative or additional content they can generate revenue from and control what content the user has access to. Flexible content distribution platform and flexible service provisioning are by-products and not the core issues.
With IMS revenue generation may not be focused on the end user. It could well be based on a sharing revenue with 3rd party content providers or by selling to marketers or retailers alike access to customers.
I am not convinced that the need for IMS stems from the desire to "converge". The main objective for IMS is to give the operators a mechanism by which they can charge for any user activity and control the content distributed over their network. With the introduction of 3G data access the operators realised that the future is bleak if they simply offered mobile data speeds for users to access the (mostly) free Internet content. Therefore they wanted a mechanism by which they offer an alternative or additional content they can generate revenue from and control what content the user has access to. Flexible content distribution platform and flexible service provisioning are by-products and not the core issues.
With IMS revenue generation may not be focused on the end user. It could well be based on a sharing revenue with 3rd party content providers or by selling to marketers or retailers alike access to customers.
27 Nov 2006
VoIP Episode 6: To VoIP or not to VoIP, that is the question
Cellular operators seem to be confused about VoIP. On one hand they seem to think that the whole world is going IP, hence VoIP is inevitable. On the other hand, they do not want to undermine their number one profitable application: trunked voice. There is also confusion about benefits of carrying VoIP on cellular radio access networks.
Most cellular operators see VoIP as a dangerous proposition because it cannibalises their stable voice market share. That's why, until recently, any talk about VoIP over cellular was accompanied by a view that VoIP traffic will be controlled and billed by the operators in a very similar fashion to traditional circuit switched voice. Therefore the concepts of a myriad of sophisticated "boxes" were introduced to enable quality controlled VoIP (as opposed to best effort VoIP over the Internet) along with all the added value services associated with the IMS architecture. So the emphasis is on the user experience, and perhaps the vision is to do voice "sessions" in the same way you use your Instant Messenger with the added guarantee of quality. Operators don't want to merely become bit pipes for other content providers, and they dread the prospects of following the footsteps of DSL providers.
The other driver is to have a more integrated core network. This may be true in the long term, because legacy networks will stay for some time (perhaps a generation) before they get obsolete, so the vision of one integrated core still needs sometime to materialise. Incidentally, convergence (I know, an overused word these days) is really about using less boxes to carry different types of traffic, and it is not necessarily about everything becoming IP based.
In a nutshell, the vision is to bring VoIP to cellular radio in a controlled fashion that guarantees the operator's grip on the revenue. UMTS operators can stop users from using their packet access to transmit/receive VoIP traffic. There are network devices that can "sniff" the types of packets generated by users and if you are running a Skype client for example, they can block it for you. Nokia launched a VoIP blocker to help operators stop cheap peer-to-peer VoIP from competing with their own voice services.
So on one extreme, the operator may want to run the business as a "walled garden" and have full control over content and traffic. The other extreme is to run the business following the ISP model: they give the user a bit pipe (could be fat or slim) and the user does whatever he likes with it. Content providers provide their services to the end user independently of the operator in the same way it is done over the Internet.
The cellular business could also be run in a balanced way between these two extremes, perhaps by "cherry picking" content providers that are allowed to promote their service over the cellular network. Perhaps the cellular business model can shift from generating income from the end user to making money from content providers instead. Perhaps they can diversify their business and get into making content themselves to compete in equal footing with everyone else.
3 has recently announced its launch of mobile Internet in the UK. Their model is "all you can eat" flat fee. They are partnering with Skype, eBay and Google. It is yet to be clear how much control they will have over the traffic, and what revenue streams they will have together with their new Internet partners. It seems likely they followed a "we give you the pipe you do the skype!" model. If this turns out to be true, it can be considered as the end of the cellular industry in the UK as we know it. peer-to-peer VoIP does not need any "expensive?" boxes to control it or monitor it. Users should not expect a quality better than VoIP over the Internet though; this is not trunked grade voice. So It is all about extending the Internet experience to the mobile world in this case, full stop. In contrast to this, do you remember the "IMS tax" we talked about before? It is about the quality vs complexity tradeoff again.
3 has got nothing to loose, they have a loss making business and Hutchinson was rumoured to be thinking of selling the business (I hope they will not sell to Orascom, otherwise the egyptians will run it in the same way they run EgyptAir) , therefore it is not surprising to hear that they have decided to try the rather uninspiring ISP model.
On the other hand, incumbents like Vodafone are not doing any better. They have an endemic problem of lack of creativity and ability to introduce new exciting services. The are too frightened of competition from fixed wireless and fixed wired, and feel the threat coming from every corner.
Cellular operators tend to forget that they have two very strong commodities which the others do not have. The first is mobility. The fact that they can support an advanced level of mobility is something competitors can not even get close to, at least not in the short to medium run. Roaming, portability and ubiquity flow naturally from this.
The other strong commodity they have is the location information, which many services and applications can be wrapped around. In their short sighted and rather uncreative vision, they have only looked at things like emergency services and mapping applications, but very little real work on any real creative applications.
Meanwhile, most operators are still stuck in the same corner thinking: shall we VoIP or shall we not?
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Most cellular operators see VoIP as a dangerous proposition because it cannibalises their stable voice market share. That's why, until recently, any talk about VoIP over cellular was accompanied by a view that VoIP traffic will be controlled and billed by the operators in a very similar fashion to traditional circuit switched voice. Therefore the concepts of a myriad of sophisticated "boxes" were introduced to enable quality controlled VoIP (as opposed to best effort VoIP over the Internet) along with all the added value services associated with the IMS architecture. So the emphasis is on the user experience, and perhaps the vision is to do voice "sessions" in the same way you use your Instant Messenger with the added guarantee of quality. Operators don't want to merely become bit pipes for other content providers, and they dread the prospects of following the footsteps of DSL providers.
The other driver is to have a more integrated core network. This may be true in the long term, because legacy networks will stay for some time (perhaps a generation) before they get obsolete, so the vision of one integrated core still needs sometime to materialise. Incidentally, convergence (I know, an overused word these days) is really about using less boxes to carry different types of traffic, and it is not necessarily about everything becoming IP based.
In a nutshell, the vision is to bring VoIP to cellular radio in a controlled fashion that guarantees the operator's grip on the revenue. UMTS operators can stop users from using their packet access to transmit/receive VoIP traffic. There are network devices that can "sniff" the types of packets generated by users and if you are running a Skype client for example, they can block it for you. Nokia launched a VoIP blocker to help operators stop cheap peer-to-peer VoIP from competing with their own voice services.
So on one extreme, the operator may want to run the business as a "walled garden" and have full control over content and traffic. The other extreme is to run the business following the ISP model: they give the user a bit pipe (could be fat or slim) and the user does whatever he likes with it. Content providers provide their services to the end user independently of the operator in the same way it is done over the Internet.
The cellular business could also be run in a balanced way between these two extremes, perhaps by "cherry picking" content providers that are allowed to promote their service over the cellular network. Perhaps the cellular business model can shift from generating income from the end user to making money from content providers instead. Perhaps they can diversify their business and get into making content themselves to compete in equal footing with everyone else.
3 has recently announced its launch of mobile Internet in the UK. Their model is "all you can eat" flat fee. They are partnering with Skype, eBay and Google. It is yet to be clear how much control they will have over the traffic, and what revenue streams they will have together with their new Internet partners. It seems likely they followed a "we give you the pipe you do the skype!" model. If this turns out to be true, it can be considered as the end of the cellular industry in the UK as we know it. peer-to-peer VoIP does not need any "expensive?" boxes to control it or monitor it. Users should not expect a quality better than VoIP over the Internet though; this is not trunked grade voice. So It is all about extending the Internet experience to the mobile world in this case, full stop. In contrast to this, do you remember the "IMS tax" we talked about before? It is about the quality vs complexity tradeoff again.
3 has got nothing to loose, they have a loss making business and Hutchinson was rumoured to be thinking of selling the business (I hope they will not sell to Orascom, otherwise the egyptians will run it in the same way they run EgyptAir) , therefore it is not surprising to hear that they have decided to try the rather uninspiring ISP model.
On the other hand, incumbents like Vodafone are not doing any better. They have an endemic problem of lack of creativity and ability to introduce new exciting services. The are too frightened of competition from fixed wireless and fixed wired, and feel the threat coming from every corner.
Cellular operators tend to forget that they have two very strong commodities which the others do not have. The first is mobility. The fact that they can support an advanced level of mobility is something competitors can not even get close to, at least not in the short to medium run. Roaming, portability and ubiquity flow naturally from this.
The other strong commodity they have is the location information, which many services and applications can be wrapped around. In their short sighted and rather uncreative vision, they have only looked at things like emergency services and mapping applications, but very little real work on any real creative applications.
Meanwhile, most operators are still stuck in the same corner thinking: shall we VoIP or shall we not?
© Copyright belongs to the author. Do not cite or quote without the express permission of the author
26 Nov 2006
VoIP Episode 5: VoIP over UMTS mouth-to-ear delay
I have received some queries about the delay encountered by VoIP calls. Thanks for the interaction and questions, keep them coming.
In this post I will summarise the various reasons that cause delay of VoIP speech over a UMTS network, or over any network for that matter.
I should mention here that I am not trying to show that VoIP over UMTS is any better or worse than conventional UMTS (I will only do that for a high consultancy fee! ;-) ).
Let us first "dissect" a VoIP call:
Before you start a VoIP call (and during the call) signalling messages are exchanged between the two VoIP terminals and possibly with some other network elements. These are carried using the Session Initiation Protocol (SIP). When you talk into your handset speaker, your analogue voice signal is "encoded" as a string of bits. A number of bits are then packed together in one packet and all the necessary headers are added to it. These packets are then transmitted over the network. They propagate through one or more packet switched networks before they reach their destination. At the destination, the received packets are then reordered and a decoder transforms the digital bits to an audible audio signal.
The sources of delay are numerous:
I hope this answered your questions. I will talk about how some of the advanced 3GPP features will address some of the delay issues in a coming post, so stay tuned!.
© Copyright belongs to the author. Do not cite or quote without the express permission of the author
In this post I will summarise the various reasons that cause delay of VoIP speech over a UMTS network, or over any network for that matter.
I should mention here that I am not trying to show that VoIP over UMTS is any better or worse than conventional UMTS (I will only do that for a high consultancy fee! ;-) ).
Let us first "dissect" a VoIP call:
Before you start a VoIP call (and during the call) signalling messages are exchanged between the two VoIP terminals and possibly with some other network elements. These are carried using the Session Initiation Protocol (SIP). When you talk into your handset speaker, your analogue voice signal is "encoded" as a string of bits. A number of bits are then packed together in one packet and all the necessary headers are added to it. These packets are then transmitted over the network. They propagate through one or more packet switched networks before they reach their destination. At the destination, the received packets are then reordered and a decoder transforms the digital bits to an audible audio signal.
The sources of delay are numerous:
- First, there is the coding delay, which is the time spent on transforming your speech into a digital stream of bits. This can be minimised by powerful DSP/electronics.
- Then there is the time it takes to compile a packet and add headers to it (packetisation delay). For example, if a packet contains X voice samples, then it has experienced a delay from the instant of the first sample to the instant the packet was complete and ready for transmission. Obviously the bigger the packets are, the longer is the packetisation delay.
- There is also the propagation delay. This is the time the packet takes to traverse the various networks before it reaches its destination. This could be the propagation time over the air interface, or over the various packet core elements. This is essentially determined by the speed of the different physical mediums over which VoIP packets are transmitted: wires, optical cables, radio ...etc
- In addition to this, there is the summation of queuing delays encountered by the packet at each node in the network(s). For example, we have seen in a previous post that a VoIP packet may have to queue for a HSDPA radio resource, or the packet may have to queue at some of the routers and switches before it reaches its destination. The various routers and switches along the route of the packet can be loaded differently, so some packets may be delayed more than others.
- When the packets arrive at the destination, they may not arrive in the right order, because they may traverse different routes before arriving at the destination and because some of them are delayed more than others. Therefore, the receiver has to buffer the packets in order to wait for the slower ones and reorder the packets before submitting them to the decoder. This is called "De-jittering". The de-jittering introduces another delay before the packets are decoded into an audible signal again.
- There is also the delay associated with call signalling. You can not start talking until it rings at the other side and the called party answers. Because of the large SIP messages this delay could also be long. The same issues arises when the call ends, which does not really affect the user perceptions as much as it keeps some network resources tied up for a while.
I hope this answered your questions. I will talk about how some of the advanced 3GPP features will address some of the delay issues in a coming post, so stay tuned!.
© Copyright belongs to the author. Do not cite or quote without the express permission of the author
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