Enterprise

Can robots outperform humans for in-building small cell testing?

Commscope robot introAutomation is a growing theme for many aspects of life today. Many of the manual and even highly skilled processes of the past are being superseded by alternative, innovative methods. Recently, I visited CommScope’s R&D lab at Chelmsford, near Boston, and saw for myself how they’ve pioneered using an autonomous robot to walk their building and conduct extensive wireless performance testing.

Robot applications growing in scope

The Sci-Fi vision of humanoid robots is thankfully still quite some time off, although I heard of “PiBots” being developed to fly aircraft. Uber has a vision of self-driving cars, replacing the need to buy your own.

Meanwhile, several simpler more mundane robot applications are already mainstream. Automated lawn mowers and domestic vacuum cleaners are good examples of repeatable, relatively mundane tasks for which robots are suitable.

Jay Weitzen, CommScope’s director of RAN performance and analytics for small cells, wanted to enhance their ongoing product testing by making large numbers of repeatable RF measurements throughout a real office building to assess and verify small cell performance.

For this mission, Jay’s team decided to enlist robotic help. They selected the TurtleBot open-source platform.  It resembles a domestic vacuum cleaner robot with a similar footprint but larger height, to accommodate connected equipment and sensors, and a software development kit that supports extensive control and customisation. It is managed by an on-board laptop connected to a laser rangefinder, internal gyroscope and wheel odometry that together track its position accurately to within a foot at all times. This system navigates around the rooms, discovering and exploring according to how it has been pre-configured.

A second on-board laptop connects to one or more UEs (smartphone devices) that conduct extensive RF measurements and simulate specific scenarios during the tests.

A custom designed post-processing application analyses data from both and reports results.

Commscope robot

The operational area includes any accessible floor space including underneath desks, inside meeting rooms, offices, cubes and open spaces. While it can’t open doors, it knows its limits and is smart enough not to fall down the stairs. The test area can be mapped against a floorplan diagram for reporting purposes.

Weitzen explained: “Unlike manual walk testing, the procedure is extremely thorough and includes every accessible area. It’s repeatable, so subsequent software releases can be thoroughly regression-tested against previous results. SON and handover testing can be methodical and repeatedly tested with different configurations.” He added that “Robots don’t get tired, bored or sick and are very good at otherwise monotonous, repeated activities.”

Cell Virtualisation in Action

In April I wrote about CommScope’s cell virtualisation technology – a method for multiplying capacity within a single physical cell, by reusing the same physical resource blocks (PRBs) with different user data, when the system determines that two users are sufficiently far apart that their signals, delivered by different radio points, will not interfere. During my visit, I saw a live demonstration of it.

The demo started with two UEs positioned directly under a single Radio Point. Because they are being served by the same Radio Point, there is no opportunity for reuse. A laptop screen showed simultaneous data streaming rates to two smartphones. Each device gets approximately 60 Mbps, for a total of around 120Mbps for the two when co-located.

Then, one of the two smartphones moves around the office where it can take advantage of other radio nodes within the same physical cell, until both achieve 120Mbps each, for a total of about 240 Mbps, or double the capacity.

This is tremendous throughput with seamless transition in a real-world office, rather than purely test lab environment.

OneCell results

The level of detail from such extensive in-building testing is impressive. What CommScope engineers look for are not just signal strength levels, but signal quality, especially at cell edge boundaries covered by adjacent radio nodes.

Although there are three radio nodes covering the floor of their building, each smartphone only sees one common physical cell ID (hence the name OneCell). The chart below shows the continuity and thorough signal coverage, with the brown areas illustrating a separate signal emulating an outdoor macrocell for use when leaving/entering the building.

CommScope Aircell CellID

Signal quality is arguably even more important, and the chart below shows the extremely high signal/noise ratio: 20 dB or greater across 95% of test locations. This leads to extremely high throughput because very high modulation rates can be used. The system achieves high quality service throughout, with Channel Quality Index of 11 or greater (out of a possible 15) in 95% of test locations. This provides all users with the maximum throughput rates that LTE offers – and even more with cell virtualisation. [See sidebar on right hand side: Cell Virtualisation in Action]

CommScope Aircell SNR

Summary

Innovation comes in many shapes and forms.

CommScope has pioneered an effective method of thoroughly walk-testing their in-building small cell system. While not required for use in every real-world commercial deployment, it serves an important purpose to validate and verify technical performance.

While I don’t believe that on-site installers have too much to worry about with robots replacing their job roles, it does indirectly improve the sophistication of in-building solutions and ensures the system is robust and resilient.

Hits : 2094

Comments   

#1 Smartie Pants said: 
Commscope should add this to the iRobot Roomba 980. That way you can have continuous walk tests while vacuuming the floor.
0 Quote 2016-10-20 17:55
 
#2 ThinkSmallCell said: 
@Smartie Pants: Interesting idea but I wonder if the electrical interference from a powerful vacuum cleaner motor might affect the measurements taken.
0 Quote 2016-10-24 10:06
 
  • 4

    more

    Residential

    Residential

    A significant number of users continue to report poor mobile coverage in their homes. There will always be areas which are uneconomic for mobile operator to reach. They range from rural areas

    ...
  • 4

    more

    Enterprise

    Enterprise

    The term Enterprise addresses any non-residential in-building including hotels, convention centres, transport hubs, offices, hospitals and retail outlets. It's not just intended for businesses to

    ...
  • 4

    more

    Urban

    Urban

    Urban small cells (sometimes also named metrocells) are compact and discrete mobile phone basestations, unobstrusively located in urban areas. They can be mounted on lampposts, positioned on the

    ...
  • 4

    more

    Rural

    Rural

    A rural small cell is a low power mobile phone base station designed to bring mobile phone service to small pockets of population in remote rural areas. These could be hamlets, small villages or

    ...
Categories
Backhaul Timing and Sync Chipsets Wi-Fi LTE TDD Regional

Popular Categories

Follow us on...

footer-logo

Search