If Femtocells were to operate on a frequency that is shared with the macro network in a restricted mode (i.e. only specific users can access a particular Femtocell), there is a concern that interference between the two layers may create a doomsday scenario.
For some reason, many think that the uplink interference from Femto users will jam the macro recievers and cause macro uplink coverage to deterioate. Some technologists and vendors have responded to this challange by developing extremely complex techniques. I have seen documents on both FemtoForum and 3GPP talking about things like:
- an interface between the macro layer and femtocells to exchange radio specific contexts.
- A "cognitive pilot channel" proposal that seems to be at least 15 years ahead of its time.
- Proposals to use uplink interference cancellation technology in femtocells.
- Suggestions that only LTE access points and release 8 (or 9) handsets will eliminate the interference problem.
All of the above is very interesting for a technologist. Ofcourse there is always a way to make things better, but there are also other considerations: value added, cost, market segment, technology application, market drivers ...etc, otherwise we would be all driving a Ferrari or a Porsche.
Looking at this interference issue, I can't help point out a number of things:
- I believe that more than half of femtocell deployments will end up using a dedicated carrier.
- In the absence of a femtocell, the user will go on the macro network and will create an amount of noise rise anyway. When you put a femtocell close-by the user will radiate less power and create less noise rise to the macro site. There is at least a 25-30dB reduction in path loss, so the femto users will radiate much less power than if they are using the nearest macro cell.
- A residential femtocell will only support a very limited number of users, so the interfernce limit ishardly ever reached and additional uplink interference from macro users operating in the vicinity will hardly block the femtocell uplink.
Is is possible that theso called interference problem is nothing but a big red herring?
Showing posts with label Femto. Show all posts
Showing posts with label Femto. Show all posts
25 Nov 2008
The hidden benefits of femtocells
I have spent some time now looking at various femtocell business cases and find it very interesting how creative some of the operators are when it comes to using femtocells to generate new revenue streams.
It occured to me that sometimes it's the straightforward and simple things that get over looked in these business cases, and I wanted to go back to basics and look at the simplest scenario of using a femtocell to generate revenue.
One of the revenue streams that operators rely on is the income from call termination charges. All operators negotaite commerical wholesale interconnection agreements with other operators, these are often wholesale agreements regulating the conditions under which the agreement parties can connect to each other.
The call termination rate is a wholesale price one network pays in order to terminate a call originating from its own network to a destination in the other network. Typically, the call termination rates are based on an average cost of delivery plus a margin.
With the increased regulatory pressure to reduce call termination rates (e.g. in UK and Europe) operators are having to drop their margins and have to live on a smaller revenue stream from terminating calls from other networks. Changes to termination rates is having a significant impact on the profits of mobile telecoms companies.
The average cost of delivering mobile terminated calls is greatly reduced if the penetration of femtocells in the network is high enough. And therefore it becomes cheaper -on average - to terminate calls from other networks. This automatically translates into higher call termination profits.
It occured to me that sometimes it's the straightforward and simple things that get over looked in these business cases, and I wanted to go back to basics and look at the simplest scenario of using a femtocell to generate revenue.
One of the revenue streams that operators rely on is the income from call termination charges. All operators negotaite commerical wholesale interconnection agreements with other operators, these are often wholesale agreements regulating the conditions under which the agreement parties can connect to each other.
The call termination rate is a wholesale price one network pays in order to terminate a call originating from its own network to a destination in the other network. Typically, the call termination rates are based on an average cost of delivery plus a margin.
With the increased regulatory pressure to reduce call termination rates (e.g. in UK and Europe) operators are having to drop their margins and have to live on a smaller revenue stream from terminating calls from other networks. Changes to termination rates is having a significant impact on the profits of mobile telecoms companies.
The average cost of delivering mobile terminated calls is greatly reduced if the penetration of femtocells in the network is high enough. And therefore it becomes cheaper -on average - to terminate calls from other networks. This automatically translates into higher call termination profits.
3 Nov 2008
The business case for femtocells in the Middle East.
Etisalat is the first operator in the Middle East who shows interest in FemtoCells, and therefore they asked us at Ubiquisys to showcase their femtocell on the Etisalat stand at Gitex 2008. They branded the product “Etisalat Home Cell”.
So we took few units and demonstrated the first commercial femtocell ever in the Middle East and I ended up spending a week in Dubai during the Gitex technology week at Gulfcomms 2008.
Etisalat were very surprised at the level of maturity of this technology: first they were amazed how far the femtocell coverage can extend with only 10mW of transmission power! Then the surprise turned to admiration when we showed some of the applications of femtocells that go beyond the traditional voice + mobile broadband. The spare femtocell I had with me kept disappearing from time to time, and then I figured out that Etisalat marketing folks were borrowing it to show to journalists and TV stations covering the event . They also kept bringing VIPs to the stand from various ministries and governmental bodies as well as investors to have a look at the femtocell.
After the news hit the net and newspapers that our femtocell is at Gitex2008,
I had a busy week talking to delegates from almost every operator in the region, all keen to find out more about this interesting product. I even had a number of industry analysts who were keen to see the femtocell in action: they heard a lot about this product but never had the chance to see it in action before.
After talking to CTOs and CMOs of the top operators in the Middle East, it was very obvious why there will be a clear winning business case for 3G femtocells in the region. First of all, all operators without exception are struggling with 3G coverage indoors. One CTO has complained that UMTS technology means that the inter-site distance has to be relatively smaller in comparison to GSM in order to provide adequate indoor coverage even for the taken-for-granted voice telephony. Many operators have expansion plans to beef up their 3G networks and add sites in order to improve the quality of coverage indoors. The budgets allocated for these expansion projects can almost buy them a femtocell for every household in the country! So at least from a cost-effectiveness point of view femtocells are a clear winner
The building material and density of urban structures in the Middle East is particularly challenging to cover with a conventional network. Reinforced concrete is widely used, and towers from 30 stories upwards are springing up every day. Some of the commercial towers have expensive distributed indoor systems which are usually installed during construction. Clearly the femtocell proposition is a more cost effective way of providing indoor coverage for the office and home apartment. In summary, most of the commercial people I met immediately recognised the opportunities that femtocells can bring.
However, there are few things that have to be said about the commercial challenges to bring complete femtocell networks to the region. First of all, innovation and the desire to try new ideas is still not an outlook that you face regularly among the Middle Eastern operators. This however is slowly changing. I was positively surprised at the number of innovative offerings Etisalat was offering during the event.
Second, it did seem to me that decision making is not based on any clear or spelt out processes. For example, one operator explained that they ruled out femtocell in the past because their “3G expert” has suggested that (from a technical point of view) the idea will not fly off the ground. After checking with their3G expert, it turns out his source was a single IEE paper written by opponents of femtocells when they were trying to dilute the discussion at 3GPP (the standard body). The number of people involved in the decision process is fairly limited and not diligent enough.
A major difficulty is also lack of visibility of small and innovative companies involved in the development and making of femtocells. Operators want to deal with big vendors directly, and they get suspicious of vendors trying to become System Integrators of smaller companies. Therefore operators are more willing to work with the likes of Huawei and Alcatel. The big vendors have got the most to lose out of introducing femtocells, and therefore they take any opportunity to badmouth the concept and the technology.
All in all, it was exciting to be able to show a really cool product to a very receptive audience. I have no doubt that femtocells will change the game of Middle Eastern operators. I’ll be there again at the Comms World GSM >3G event in December.
19 Oct 2007
Femtocells are much more than cheap telephony
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.
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.
8 Aug 2007
Femto cell concept propelling "Core" activities
An interesting read on Mobile Europe discussing core network opportunities for Femto cells.
7 Aug 2007
Three areas unexploited enough by Femtocell marketing efforts
The three points talked about in every Femtocell customer meeting:
1 - Price and potential savings
2 - The indoor coverage advantage
3 - Architecture and how to integrate with existing network infrastructure
The Femtocell marketing effort can benefit from addressing three other areas:
1- Targeting new breed of customers: Most of the effort is spent towards soliciting the traditional operators (VF, FT/Orange, T-Mobile ...etc), all of which either already have mature networks or in the process of building them. One of the important selling points of the Femtocell concept is that the network can be operational from the day the first router is shipped. There is no time wasted acquiring sites and building them....etc. Therefore the prospects for new entrants are great and therefore targeting these new market entrants instead of traditional operators is a good strategy. These new entrants will have a discernibly different business model from the traditional mobile operator model.
2- High rise buildings and vertical cities: I don't know why everybody assumes that Femtocells are ideal for the typical US and European suburbia. Most people around the world live in flats in high rise buildings, tower blocks and apartments. I'd like to see the Femtocell concept pitched for this type of deployment. The benefit over typical macro deployment is easily recognisable.
3- Community Networking: I've talked about this in a previous post. This is essentially copying the FON model of community based networking. This also requires the emergence of a new breed of operators who are ready to experiment with new business models instead of the traditional linking of minutes and ARPU.
1 - Price and potential savings
2 - The indoor coverage advantage
3 - Architecture and how to integrate with existing network infrastructure
The Femtocell marketing effort can benefit from addressing three other areas:
1- Targeting new breed of customers: Most of the effort is spent towards soliciting the traditional operators (VF, FT/Orange, T-Mobile ...etc), all of which either already have mature networks or in the process of building them. One of the important selling points of the Femtocell concept is that the network can be operational from the day the first router is shipped. There is no time wasted acquiring sites and building them....etc. Therefore the prospects for new entrants are great and therefore targeting these new market entrants instead of traditional operators is a good strategy. These new entrants will have a discernibly different business model from the traditional mobile operator model.
2- High rise buildings and vertical cities: I don't know why everybody assumes that Femtocells are ideal for the typical US and European suburbia. Most people around the world live in flats in high rise buildings, tower blocks and apartments. I'd like to see the Femtocell concept pitched for this type of deployment. The benefit over typical macro deployment is easily recognisable.
3- Community Networking: I've talked about this in a previous post. This is essentially copying the FON model of community based networking. This also requires the emergence of a new breed of operators who are ready to experiment with new business models instead of the traditional linking of minutes and ARPU.
More on Google's interest in Femtocell Technology
...here are more dots to connect:
- FCC revises 700MHz band rules to facilitate "new and innovative wireless broadband services for consumers"....read here.
- Rumours about Google phone, to be available end of 2007.... read here.
- Google wants to redefine the principles of wireless market. Read here about Google's plans to replicate the openness of the broadband environment in the wireless environment. Mobile operators: prepare yourselves to become utility companies!.
- FCC revises 700MHz band rules to facilitate "new and innovative wireless broadband services for consumers"....read here.
- Rumours about Google phone, to be available end of 2007.... read here.
- Google wants to redefine the principles of wireless market. Read here about Google's plans to replicate the openness of the broadband environment in the wireless environment. Mobile operators: prepare yourselves to become utility companies!.
6 Aug 2007
Google's Interest in Femtocell technology
So why is Google interested in Femto cells?
One view is that Google may be the first new breed of mobile operators. For a green field entrant the prospects of building a distributed network using Femto Cell technology surely has some benefit: the network is operational the minute the first Femto box is plugged in the wall and no valuable time is wasted acquiring sites, radio planning and optimising coverage...etc.
Another view is that Google is interested in the potentially disruptive model of community based networking such as the one propelled by FON. Clearly Femto Cell based community networks have a similar appeal, and hence Google's interest.
One view is that Google may be the first new breed of mobile operators. For a green field entrant the prospects of building a distributed network using Femto Cell technology surely has some benefit: the network is operational the minute the first Femto box is plugged in the wall and no valuable time is wasted acquiring sites, radio planning and optimising coverage...etc.
Another view is that Google is interested in the potentially disruptive model of community based networking such as the one propelled by FON. Clearly Femto Cell based community networks have a similar appeal, and hence Google's interest.
FemtoCells on BBC News
Here is a link to an article on BBC Technology News with a good summary of the case for Femtocells from a user's and operator's points of view.
22 Jul 2007
Google invests $25 million in Ubiquisys
The recent news of Google's $25 million investment in Ubiquisys is the beggining of a major change in the race to win the Femtocell race.
While architecture, coverage and RF performance are some of the important areas to keep a close eye on, content and applications will be the major differentiating aspects. I talked in a previous post about content personalisation and customisation possibibilities with FemtoCell solutions, which is going to be an exciting area to watch over the next 6 months.
While architecture, coverage and RF performance are some of the important areas to keep a close eye on, content and applications will be the major differentiating aspects. I talked in a previous post about content personalisation and customisation possibibilities with FemtoCell solutions, which is going to be an exciting area to watch over the next 6 months.
18 Jul 2007
Indoor FemtoCells and content personalisation
One of the tooted selling points of FemtoCells is the enhanced user experience indoors. There is no doubt that in terms of radio coverage the FemtoCell will enable a more uniform and better RF signal indoors.
The story does not end there however. The underlying concept of "convergence" with FemtoCells will give content personalisation and customisation a whole new dimension. In addition to simple signal radiation, a FemtoCell router serving 2-3 mobiles can also perform a whole bunch of other tasks on behalf of users. This is a new uncharted territory with a poetic license to daydream. A variant of social networking can also emerge if it is embraced by the new breed of "converged" operators.
With Google putting effort on mobile content search, the FemtoCell era will be a very exciting and interesting period and one should expect interest in this technology to extend beyond the circle of traditional mobile operators.
The story does not end there however. The underlying concept of "convergence" with FemtoCells will give content personalisation and customisation a whole new dimension. In addition to simple signal radiation, a FemtoCell router serving 2-3 mobiles can also perform a whole bunch of other tasks on behalf of users. This is a new uncharted territory with a poetic license to daydream. A variant of social networking can also emerge if it is embraced by the new breed of "converged" operators.
With Google putting effort on mobile content search, the FemtoCell era will be a very exciting and interesting period and one should expect interest in this technology to extend beyond the circle of traditional mobile operators.
13 Jul 2007
News coverage of the Femto Forum
Telecoms.com (Informa's telecomm business intelligence reporting outlet) has some interesting and insightful coverage of the Femto Forum meeting that took place in London on first week of July.
The article quotes Will Franks, CTO of Ubiquisys, as well as Dr. Simon Saunders, the newly appointed Chairman of the Femto Forum on the importance of bringing the femto vendors together and collaborate to reduce or eleminate femto solution fragmentation. There are various proposed architectures and it seems that one of the aims of the Femto Forum is to try to converge these solutions into a comprehensive standard that facilitates inter-working.
The article quotes Will Franks, CTO of Ubiquisys, as well as Dr. Simon Saunders, the newly appointed Chairman of the Femto Forum on the importance of bringing the femto vendors together and collaborate to reduce or eleminate femto solution fragmentation. There are various proposed architectures and it seems that one of the aims of the Femto Forum is to try to converge these solutions into a comprehensive standard that facilitates inter-working.
11 Jul 2007
ABI research femtocell vendor ranking results
This has been out for a while, I don't know why I kept delaying linking to it:
ABI research has ranked the various femtocell vendors. Check the news release here.
Their ranking criteria is based on two aspects: Implemention and Innovation. This ranking is by no means a ranking of the femtocell prodcuts only. It also takes into account the overall position of the relavent company/division in terms of finances and partnerships. (you can see the criteria here).
Based on the matrix, ABI research has compiled a list of the top 10 femtocell vendors. The top 3 are: Ubiquisys, ip.access and RadioFrame networks.
One thing that surprised me is that Alcatel-Lucent is listed as number 4, which I thought is rather over rated considering that their offering oscilates between an imaginary concept or a modified picocell product ( not purpose built as a femto product from the outset). This ofcourse depends on who you talk to in Alcatel-Lucent: French or American.
ABI research has ranked the various femtocell vendors. Check the news release here.
Their ranking criteria is based on two aspects: Implemention and Innovation. This ranking is by no means a ranking of the femtocell prodcuts only. It also takes into account the overall position of the relavent company/division in terms of finances and partnerships. (you can see the criteria here).
Based on the matrix, ABI research has compiled a list of the top 10 femtocell vendors. The top 3 are: Ubiquisys, ip.access and RadioFrame networks.
One thing that surprised me is that Alcatel-Lucent is listed as number 4, which I thought is rather over rated considering that their offering oscilates between an imaginary concept or a modified picocell product ( not purpose built as a femto product from the outset). This ofcourse depends on who you talk to in Alcatel-Lucent: French or American.
Reuters report on Femtocell featuring ip.access
Reuters made a short report on a femtocell demo organised by ip.access. Check it out here. (Thanks to Mr. Adnan Boustany from PicoChip for sending the link).
What I like the most about ip.access's approach is that they realised the importance of effective marketing to win customer confidence. In terms of technical performance and features I don't think they are far ahead or behind the other major femtocell developers. Nevertheless it seems their relentless marketing effort is paying off.
What I like the most about ip.access's approach is that they realised the importance of effective marketing to win customer confidence. In terms of technical performance and features I don't think they are far ahead or behind the other major femtocell developers. Nevertheless it seems their relentless marketing effort is paying off.
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.
5 Jul 2007
Femtocell Forecasts
Cellular News published an interesting short article suggesting that femtocell shipments will reach 36million in 2012, which in my view a rather conservative estimate. The estimate is contingent on a couple of big operators tidying up their messy business models. If operators grasp the big potential offered by the femto concept, then one can easily predict an estimate closer to 100 million plus. Nevertheless I perfectly understand why other experts do not see it this way.
An interesting quote in the article mentioned above:
"...no matter how attractive the service offerings a femtocell-based solution can bring, the sheer savings from backhaul and energy costs could equate to over $70 billion by 2012, outshining service revenues and providing enough financial incentive for carriers to actively support this solution".
Obviously, the operators that will gain the most are the ones that do not have yet a fully deployed 3G infrastructure.
An interesting quote in the article mentioned above:
"...no matter how attractive the service offerings a femtocell-based solution can bring, the sheer savings from backhaul and energy costs could equate to over $70 billion by 2012, outshining service revenues and providing enough financial incentive for carriers to actively support this solution".
Obviously, the operators that will gain the most are the ones that do not have yet a fully deployed 3G infrastructure.
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.
14 Feb 2007
The advent of Femto cells - cont'd
Both Epen and Martin made valuable comments on my last posting, so I thought that expanding some of the ideas is in place.
From the consumer point of view, reduced call prices are definitely an important aspect of Femto cells. As for the interference aspect, whether Femto cells will cause more or less interference to Macro cells is debatable. On one hand the signal will be contained within indoors. On the other hand it is likely there will be so many of them. Also, there has to be a reasonable signal penetration into (or out of) buildings to facilitate handover between the two layers.
Will DSL providers get a piece of the pie? It depends who the DSL provider is. As Martin suggested, there are many operators buying DSL assets and are thinking of service "convergence" on the long run. If you are a mere DSL provider, your business model is unlikely to be affected much with Femto cells. Somebody is paying for the DSL subscription (could be the consumer, but could be the operator too), and that's all that matters. If you are someone competing with mobile operators (e.g. BT), then it is likely they will put any hurdle they can think of in the way of Femto cells, unless they make some money out of it.
Femto cells will definitely face fierce competition. If mobile operators loose the battle, at least they can claim that they tried, instead of sitting back and watching the market slip away. They may well loose, but they will loose more by not trying.
There are many handsets with WiFi capabilities around. Whether someone would want to use Skype and ditch the conventional mobile network is a matter of personal preference. For the time being, only technology suave people with love of experimentation do this.
There are also many hurdles that internet based VoIP (e.g. Skype) has to pass before it is adopted on a full scale for mobility. For example, seamless call transfer between the home cell and Macro layer can not happen if you use a simple VoIP routed over the internet: the mobile operator has to be involved somehow. This makes the Femto solution more appealing, because the call is managed easily and seamlessly.
It is not perceived that wireless calls over WiFi will pick up on a large scale, simply because powerful operators (who by the way spent billions on spectrum) will not allow it to happen. So the issue of mobility support is intertwined with the spectrum license and the regulatory aspects associated with it. For example it is not permitted to support mobility on a system using the fixed wireless broadband spectrum in UK.
All in all, here is a summary of all the factors that will influence the Femto cell strategies going forward:
Indeed... only time will tell.
From the consumer point of view, reduced call prices are definitely an important aspect of Femto cells. As for the interference aspect, whether Femto cells will cause more or less interference to Macro cells is debatable. On one hand the signal will be contained within indoors. On the other hand it is likely there will be so many of them. Also, there has to be a reasonable signal penetration into (or out of) buildings to facilitate handover between the two layers.
Will DSL providers get a piece of the pie? It depends who the DSL provider is. As Martin suggested, there are many operators buying DSL assets and are thinking of service "convergence" on the long run. If you are a mere DSL provider, your business model is unlikely to be affected much with Femto cells. Somebody is paying for the DSL subscription (could be the consumer, but could be the operator too), and that's all that matters. If you are someone competing with mobile operators (e.g. BT), then it is likely they will put any hurdle they can think of in the way of Femto cells, unless they make some money out of it.
Femto cells will definitely face fierce competition. If mobile operators loose the battle, at least they can claim that they tried, instead of sitting back and watching the market slip away. They may well loose, but they will loose more by not trying.
There are many handsets with WiFi capabilities around. Whether someone would want to use Skype and ditch the conventional mobile network is a matter of personal preference. For the time being, only technology suave people with love of experimentation do this.
There are also many hurdles that internet based VoIP (e.g. Skype) has to pass before it is adopted on a full scale for mobility. For example, seamless call transfer between the home cell and Macro layer can not happen if you use a simple VoIP routed over the internet: the mobile operator has to be involved somehow. This makes the Femto solution more appealing, because the call is managed easily and seamlessly.
It is not perceived that wireless calls over WiFi will pick up on a large scale, simply because powerful operators (who by the way spent billions on spectrum) will not allow it to happen. So the issue of mobility support is intertwined with the spectrum license and the regulatory aspects associated with it. For example it is not permitted to support mobility on a system using the fixed wireless broadband spectrum in UK.
All in all, here is a summary of all the factors that will influence the Femto cell strategies going forward:
- License: Is it needed, who owns it and what does it cover? What spectrum?
- Mobility: Will seamless communication (handover,routing of incoming and outgoing calls) be part of any competing solutions?
- Content: who has control of it, and how much will it cost to access it?
- Backhaul: who controls DSL backhaul?
- Regulatory: how will the spectrum be allocated and what are the conditions attached to it by the regulatory bodies?
- HW costs: What volumes? Economies of scale? Cost in handset or router?
Indeed... only time will tell.
9 Feb 2007
The advent of Femto Cells
Home base station solutions, also called Femto cells have recently attracted a lot of attention. The idea is to give the mobile user a small box similar to wireless routers, which provides mobile cellular coverage at home. But why would mobile operators want to do that?
In order to answer this question, one has to look at what mobile operators are competing against. Fixed line carriers and DSL service providers are seriously threatening the mobile business by offering new products centered around Fixed Mobile Convergence, which in essence utilises wireless access technology to capture mobile users when at home, and divert their mobile originated voice and data calls to the fixed line network.
Mobile operators found themselves in a predicament: the traditional Macro cellular networks are not able to compete with what DSL service providers can offer, neither from a cost structure point of view, nor in terms of access speeds. (of course the mobile operators are partly to blame because they picked the wrong battle by trying to compete on the basis of access speeds rather than mobile centric applications).
A home base station or femto cell can help mobile operators in many ways. First they can compete directly with other home access solutions which rely on other types of access technology such as WiFi or WiMax. This is because low cost mobile handsets are widely available, whereas dual mode handsets with WiFi capabilities are pricey and still limited in variety.
The femto cell will also enable the operator to cater for subscribers where the service is most needed. Compare this with traditional macro deployment where the infrastructure is first built in places where subscribers are "likely" to appear and even before subscribers start using the network. A femto cell also circumvents the issue of outdoor-to-indoor propagation which typically kills the capacity of 3G and 3.5G systems.
The deployment costs associated with a femto cell are marginal in comparison with Macro cell deployment. This is because the customer is providing the "real estate" to keep the box, the power, as well as the backhaul (e.g. DSL subscription). I don't assume here that Femto cells will replace the macro layer, nevertheless the extent of investment in the macro layer will be considerably less.
Femto cells will also enable the operator to offer creative and disruptive tariffs to directly compete with fixed line. Home zone offers can also be more effective than traditional home zone offers using macro cells which extend for kilometers sometimes (because they rely on a cell ID parameter).
So where is the catch? I will discuss the downside in a future post.
In order to answer this question, one has to look at what mobile operators are competing against. Fixed line carriers and DSL service providers are seriously threatening the mobile business by offering new products centered around Fixed Mobile Convergence, which in essence utilises wireless access technology to capture mobile users when at home, and divert their mobile originated voice and data calls to the fixed line network.
Mobile operators found themselves in a predicament: the traditional Macro cellular networks are not able to compete with what DSL service providers can offer, neither from a cost structure point of view, nor in terms of access speeds. (of course the mobile operators are partly to blame because they picked the wrong battle by trying to compete on the basis of access speeds rather than mobile centric applications).
A home base station or femto cell can help mobile operators in many ways. First they can compete directly with other home access solutions which rely on other types of access technology such as WiFi or WiMax. This is because low cost mobile handsets are widely available, whereas dual mode handsets with WiFi capabilities are pricey and still limited in variety.
The femto cell will also enable the operator to cater for subscribers where the service is most needed. Compare this with traditional macro deployment where the infrastructure is first built in places where subscribers are "likely" to appear and even before subscribers start using the network. A femto cell also circumvents the issue of outdoor-to-indoor propagation which typically kills the capacity of 3G and 3.5G systems.
The deployment costs associated with a femto cell are marginal in comparison with Macro cell deployment. This is because the customer is providing the "real estate" to keep the box, the power, as well as the backhaul (e.g. DSL subscription). I don't assume here that Femto cells will replace the macro layer, nevertheless the extent of investment in the macro layer will be considerably less.
Femto cells will also enable the operator to offer creative and disruptive tariffs to directly compete with fixed line. Home zone offers can also be more effective than traditional home zone offers using macro cells which extend for kilometers sometimes (because they rely on a cell ID parameter).
So where is the catch? I will discuss the downside in a future post.
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