Friday, 5 May 2017

Sprint's Magic Box


Is Sprint doing Small Cells? That's a question probably asked too many times. Back in January, their COO G√ľnther Ottendorfer said the company’s small cell partners conducted a range of trials last year in order to determine fast and efficient methods to deploy small cells, a situation he said led to some misunderstandings in the market. However, he said those trials are largely behind the carrier and that he expects the carrier’s small cell efforts to expand this year.

“There was a learning process in 2016. We did a lot of trials in the beginning. We had some trials that led to misunderstandings, when you have a lot of boxes there because you were trialing different things, different—for example—transmission methods,” said Ottendorfer, Sprint’s chief operating officer for Technology, in a recent interview with FierceWireless. “But now we have streamlined the concepts and so I’m very confident that with streamlined and very elegant small cell solutions we will have a good rollout this year.”

They again mentioned about their small cells commitment at MWC. Finally this week, they announced the Magic Box.

Sprint has billed it as "World’s First All-Wireless Small Cell". This is a point where I would disagree with them, mainly for two reasons.The first being that for an all-wireless claim, they have to get wireless power to the small cell and secondly, this has already been done for a while. I have explained about In-band backhaul here and have provided examples of how Parallel Wireless has been using this for a while.

The Magic Box is made by Airspan and is 4G/LTE only in band 41 (2500 MHz TD-LTE). One of these units provide an average coverage of 30,000 square feet indoors and can benefit adjacent Sprint customers inside the building. The signal can also extend coverage 100 meters outside a building, benefiting customers in nearby buildings and improving street–level network performance. It does not use the closed subscriber group (CSG) feature hence anyone can camp on it and use it.


Sprint has a large amount of 2.5GHz spectrum available, as a result they are able to use dedicated spectrum for the Magic Box. This ensures that interference is kept to minimum. They also announced the availability of HPUE that will allow this band reach to improve. See my blog post here for details.

“It’s a far cry from just a repeater,” he said, explaining that it improves the efficiency of the network as long as it has a good connection to the macro cell. It will work with any Sprint phones using 2.5 GHz. The backhaul channel uses 2.5 GHz or 1.9 GHz, but ideally it would use 2.5 GHz because that offers a lot more capacity.

The Magic Box includes self-organizing network (SON) capabilities and operates on its own channel in Sprint’s spectrum, allowing it to decrease the noise level and increase the capacity of the overall system, which is the big difference from repeaters, explained Sprint Technology COO Guenther Ottendorfer.

Some of the details I couldn't find but hopefully some of the readers would know and can answer are:
  • Whats the power output of these small cells?
  • I am assuming they will support VoLTE calling for voice - even though generally that feature is transparent to small cells?
  • Does the small cell radiate a single 20MHz channel?
  • Does the backhaul do carrier aggregation?

Further Reading:

1 comment:

  1. "In Band Repeating" is not new, It has been around since GSM days in Mid 1990s. Technology evolved 2G to 3G to 4G LTE and concept of "in band repeating" also evolved with each generation of wireless technology. Although its good for instant coverage and less overhead for configuration and optimization, it does not enhance capacity and adds more latency. Good article Zahid!

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