你是Vodafone femtocell的用户。你对这个产品满意吗？

我是最早的Vodafone接入网关的商业用户，现在的名字叫SureSignal。12个月前部署的时候确实有一些因为经验不足导致的问题——比如对我的路由器重新进行配置。一旦femtocell开始工作了，我发现它可以提供非常好的语音和数据服务体验。从那个时候开始，Vodafone和Alcatel-Lucent开始提高他们的配置系统，尽管我听到一些新的客户偶尔会抱怨一些问题，我知道现在的配置过程已经改进了很多，也更加成熟。我非常乐意将这个产品推荐给其他人（我也经常这么做）。那些购买了femtocell的人通常都很满意，甚至对服务质量的提高感到惊讶。

非常高兴看到Femtocell Primer第二版面世了。这本书主要的改动有哪些？

Femtocell Primer第一版是两年前发行的。从那个时候开始，这个产业有了很大的进展。技术标准被制定并发布了，femtocell更多的使用领域被开发出来，供应商的数量也增加了很多。在这个快速发展的技术领域，我认识到这本书需要一个完整的检查来跟上时代。我也利用这个机会加入了很多图表，扩展了很多的章节，书的页数从160页增加到了250页。这书很畅销——这不是一本充斥着公式的教科书——它从基础开始，给femtocell提供了全面的、可理解的介绍。

在你的blog里，你提到很多人看穿了LTE。你能更多的解释一下吗？

使用LTE的一个重要的原因是为移动网络提供更多的数据业务的容量。在我看来，这只能通过femtocell来实现——无论是使用3G、4G还是Wifi。我们看到的对LTE的兴趣部分是来自它是跨越3G的技术——LTE可以支持更高的数据传输率，延迟低，使用频谱的效率更高。然而LTE自身并不能解决容量的问题——LTE的容量可能可以比3.5G高2-5倍。然而很多欧洲的运营商还是会首先选择继续投资3G网络，因为3G网络跟现有的终端兼容。

频谱是使用LTE的关键因素——运营商总是希望得到更多的频谱资源，如果价格合适的话。低频资源被认为是最好的选择，因为覆盖面积大，对建筑的穿透性更好。跟10年前部署3G的时候不同，LTE更使用的资源很零碎，这使得终端商很难制造出低成本的终端。

我想在低频工作的LTE会最先被部署。美国的Verizon很快就会正式部署了。NTT DoCoMo也紧接其后。为了提高数据业务的容量，我们会看到更多的小蜂窝——他们可能工作在高频率上，因为不需要覆盖太大的范围。在欧洲可能是2.6GHz.NTT DoCoMo要求行业在2012年前提供商用的LTE femtocell。

LTE有FDD和TDD模式。我看到TD-LTE对于femtocell的吸引力更大，因为高频的资源相对更便宜。

你对femtocell技术以后的关注点在哪里？

Femtocell的应用范围在过去12个月里扩展了很多。不再仅仅是家用的4通道产品，我们看到对企业级、偏远地区和地铁系统里的应用。这些不会立刻有很大的市场。我的方法是跟踪所有这些领域并且了解哪些机会在什么时间段会出现。

在接下来的一年，我想我们会看到企业级的femtocell会有很大的发展。这可能是运营商们开始实现femtocell的一个捷径。同时，家用市场会随着更多运营商部署femtocell继续发展。

中小企业在这个市场会有机会吗？看起来大公司，如华为，Alcatel-Lucent赢得了大部分的市场份额。

确实运营商只从很小的范围内选择femtocell供应商。这些供应商很多时候是系统集成商，比如NEC甚至没有自己的femtocell。我们能够看到的中小企业的机会是随着Iu-h接口的标准化，小企业会在femtocell市场展开竞争。而大公司继续提供网关和系统集成。小型的femtocell先锋企业会继续开阔技术，增加市场份额。

我发现很多femtocell的领先公司都在英国，比如Ubiquisys，ip.access，femto forum，Alcatel-Lucent。这是不是一个巧合呢？

我很幸运生活在伦敦的西部地区。这里有很多的电信企业，因此这里有很强技术实力。这包括部件供应商，比如picoChip，femtocell概念的提出者。Motorola在这里有GSM基站研发中心和工厂。Motorola路对面就是Ubiquisys和Alcatel-Lucent。北电在几英里外也有园区。剑桥地区也是一个创新基地，那里有ip.access和Airvana的UMTS研发中心。

中国的运营商现在在大规模的部署Wifi热点。你怎么看这个事情？

选择Wifi还是femtocell是个非常复杂的话题。上个月的Femtocell全球大会，我们看到很多讨论。很多运营商在使用Wifi，并且鼓励他们的客户用Wifi分流数据——这是一个成熟的技术。然而对我来说，Wifi无法满足我全部的需求。

你怎么看待中国femtocell市场?

我来过中国好几次，并且看到移动电话是多么的普及。宽带接入也是非常的广泛——这是使用femtocell非常重要的基础。我看到使用femtocell可以为三个运营商带来的效益是潜力巨大的，提供高质量的服务。难以预测是哪种选择会是最先被接受的——可选的有3G还是4G/LTE，FDD/TDD模式，还有家用/企业/Metro/乡村。

从外界看，TD-SCDMA只是中国在使用。4G TD-LTE技术可能会在中国以外的地区被接受。最后一点是对中国femtocell研发的投资。picoChip已经宣布他们北京研发中心的扩张计划，更多的软件工程师会加入。

下面是采访的英文全文：

You are one of the vodafone customers that bought femtocell. Are you satisfied with the product?

I was one of the very first commercial customers for Vodafone's Access Gateway, now renamed SureSignal. At the time of launch, now 12 months ago, there were still some teething problems to get it operational - issues with my router configuration and registration. Once it was working, I found it has given really excellent voice and data quality throughout. Since then, Vodafone and Alcatel-Lucent have improved their configuration systems and although I still hear of occasional problems with new customers, I understand it's now a much more streamlined and mature process.

I would be happy to recommend the product to others (and frequently do). Those that have bought it have generally been pleased and even surprised at the improved quality.

It is nice to see the book femtocell primer 2nd Edition Launched. What is the major update of the book?

The first edition of Femtocell Primer was published two years ago and there have been many advances in the industry since then. Technical standards have been written and released, a much wider range of possible uses has developed, and the number of vendors have increased dramatically. In this fast moving new technology, I recognised that the book needed a thorough overhaul to be brought up to date. I also took the opportunity to add in more diagrams and expand several sections increasing the page count from about 160 to 250. The book remains popular - it's not an academic textbook with detailed formula - providing a comprehensive and accessible introduction into the new technology from the ground up.

In your blog, you mentioned many people looked through LTE. Can you give us a further explanation?

One of the major reasons to adopt LTE is the need to provide substantial additional data capacity for mobile networks. In my view, this can only be achieved using small cells - whether these are 3G or 4G/LTE or WiFi is less important. We are seeing interest in LTE partly because it is technically superior to 3G - it can support higher data rates, lower latency and is spectrally more efficient. However, it won't solve the data capacity problem on its own - it is perhaps somewhere between 2 and 5 times better than 3.5G. Therefore, some operators in Europe may first continue to invest heavily in 3.5G HSPA+ because the system remains backward compatible with all existing handsets and data devices.

Frequency spectrum will be key to enabling LTE - operators would always want more frequencies if they can get them at an attractive price because they can save on basestations and cellsites. Lower frequencies, such as those released by the switchover to digital TV, are considered the best because of longer range and better in building penetration. Unlike the global 3G rollout 10 years ago, the picture for LTE spectrum is still quite fragmented, which may make it difficult for handset and device manufacturers to engineer high volume products at low cost.

I expect we'll see LTE launched at lower frequencies providing wide area coverage using macrocells at first. Verizon Wireless in the US will launch soon and NTT DoCoMo not long after. In order to provide the data capacity, we'll then see a need for many more smaller cells - these could be at a higher frequency because they don't need to be long range. Somewhere around 2.6GHz is being considered for Europe; other frequencies may be available elsewhere. NTT DoCoMo have asked the industry to provide commercial LTE femtocells for use by 2012.

LTE has both an FDD and TDD mode. I see the TD-LTE being attractive for use in femtocells where high frequency spectrum is available at low price and where replacing WiMAX.

What is your future focus on femtocell technology?

The scope of femtocells has grown dramatically over the last 12 months. No longer constrained to the residential 4-channel products, we are seeing interest in enterprise, rural and metro-femto systems. These can't all grow in volume immediately. My approach will be to track all of these developments and assess which of these opportunities are most likely and in what timeframe.

Over the next year, I think we will see greater interest in enterprise femtocells which now have greater capacity than before. These could be an easier route for operators to take when first implementing femtocells. Meanwhile, the residential market is also expected to grow with many new operators likely to announce commercial availability.

Will small/medium size vendor stand a chance in the market? Looks like large vendor like HW, ALU win bigger share of the market.

It's true that network operators are buying their femtocell solutions from a small number of large vendors, who act as system integrators. Some of these, such as NEC, don't have their own 3G femtocells and supply products from the smaller companies.

What we expect to see in the medium term is that the standard Iu-h interface will allow smaller new entrants to compete for the femtocell products while the system integration and gateways continue to be provided by the larger companies. The small pioneering femtocell vendors will exploit their technical leadership to keep ahead and increase their market share.

It is interesting to find many key players of femtocell are in UK, like Ubiquisys, ip.access, picoChip, femto forum, ALU. Is this just a coincidence?

I'm fortunate to live in an area to the west of London which thrives with telecom companies, resulting in a strong skillset in the region. This includes component vendors, such as picoChip, who were one of the founders of the femtocell concept. Motorola had their large GSM basestation R&D and manufacturing plant in Swindon, just across the road from Ubiquisys and Alcatel-Lucent. Nortel also had a major campus a few miles up the road, and I can think of many other telecoms businesses not far from here. Cambridge has also been a strong centre of innovation for telecoms from which ip.access and Airvana's UMTS R&D centre (formerly 3-Way) arose.

Chinese operators are deploying many Wifi AP in public areas. What do you think of this? Does femtocell market take off too slow?

The choice of Wi-Fi and femtocells is quite a complex topic. We saw many presentations about this at Femtocell World Summit last month. Many operators around the world are using Wi-Fi and encouraging their customers to offload data as much as possible - it's a technology that is available, built into many smartphones and low cost. However, I find it doesn't work well for me when out and about and believe that customers want a better user experience.

What do you think of the future of Chinese femtocell market?

I have visited China several times and can see how popular the use of mobile phones, smartphones and data devices has become. Broadband internet access is widespread - an essential enabler for this technology. I see a strong potential for all three national Chinese operators to adopt femtocells in order to provide high quality, high capacity service to their customers. What may be more difficult to predict is which of the several options will be most popular first - there are choices of technology 3G or 4G/LTE, choices of FDD/TDD mode and choices of residential/enterprise/metro-femto/rural.

The 3G TD-SCDMA technology used by China Mobile was seen (from outside China) as being primarily for China only, although I know it has been promoted elsewhere. The 4G TD-LTE technology, also strongly developed by Chinese vendors and building on knowledge from TD-SCDMA, could be much more acceptable and popular outside China.

A last point concerns investment in Chinese femtocell R&D, where picoChip have announced expansion plans for their Beijing design office and will add further software design engineers to their team.