How to Het Net!?

How to Het NetThere has been much written about why Het Nets are needed (running out of capacity) and when it will happen (licensed band small cell centric view of Het Nets). On the other hand, how Het Nets will happen is rarely discussed in the general media. Perhaps this is because this is a very technical discussion that does not attract the attention but for the few engineers and managers directly tasked with making Het Nets work. Or maybe in our world today sound bites are all that matter and nobody has the time to ‘look under the hood.’ Whatever the case, the how of Het Nets is what matter most in the wireless networking ecosystem. Simply put, get it wrong and your are doomed. How Het Nets will happen is pivotal with high implications end-to-end because it is fundamentally based on competing technologies which while it may coexist in some limited circumstances, economics demands a winner to achieve scale. Read more of this post

IoT at the Peak of the Hype Cycle

Hype CycleIt’s official: The ‘Internet of Things’ (IoT) is at the peak of the hype cycle. It only took 15 years to get to this point, considering the term was first coined in 1999. But the IoT of today is quite different from initial thrust which was in commercial and industrial applications. Today, consumer applications lead the hype. IoT, or IoE (as in Everything), is now highly associated with gadgets in the mind of the general public. Gadgets are what whip up talk, excitement and hype.  Tracking assets or performance of industrial machines makes for a dull discussion (unless that’s your business!), but everyone loves to talk about what the soon to be released Apple and Microsoft watches may do. All the hype makes me wonder how would one tell what will prove to be a fad and what will stick? What determines the staying power and commercial success of a device?  Anyone dares to predict? Wasn’t it IBM’s Thomas Watson who said “I think there is a world market for maybe five computers.”? And, if you say that was in 1943, then how about DEC’s Ken Olson statement some 34 years later that “there is no reason anyone would want a computer in their home!” Read more of this post

Millimeter Wave MIMO Systems for 5G Access Networks

Guest post by Faris Alfarhan*

Cellular NetworkConventionally, millimeter wave (mmW) frequency bands have been either largely overlooked or treated solely as real estate for wireless backhaul and personal indoor networks. That is mainly due to higher atmospheric attenuation loss, penetration losses, and increased absorption and scattering in rainy conditions. However, recent measurements indicate good outdoor short range coverage – of 200 meters on average – when using directive antenna beams, even when radio line of sight conditions are not met [1-3]. The propagation characteristics of mmW bands vary considerably depending on whether LOS or NLOS conditions are present. Since mmW signals experience low diffraction due to their small wavelength, LOS signals propagate in conditions similar to free space (a path loss exponent of 2 on average). NLOS signals, on the contrary, experience more significant losses and hence a pathloss exponent of 5.7 on average [3]. However, the NLOS pathloss exponent is significantly reduced when directing the Tx and Rx antenna beams towards each other. In order to overcome the increased pathloss at mmW frequencies, directional beamforming or beamsteering is used to generate narrow beams towards users. Since the required antenna size is inversely proportional to the operating frequency, mmW antenna arrays could encompass as much as 64-256 antenna elements at the base station and 4-12 elements on a mobile device. For example, the required antenna element length is about 0.5 cm at 28 GHz,whereas it is about 20 cm at 700 MHz. Figure 1 shows measurement results for the maximum coverage distance of a mmW systems operating at 28 GHz as a function of the pathloss exponent and the combined Tx-Rx antenna gains, where acceptable coverage is deemed to have an SNR of 10 dB and higher. Read more of this post

It’s All Too Good To Keep Talking About The Capacity Problem

TalkingThe capacity problem is at the heart of everything said about the wireless industry. Everybody loves to talk about this problem. To start, it is easy to give examples of exploding data consumption forecasts or quote numbers on mobile applications such as Facebook, Twitter , Instagram and many others. I suspect that the capacity problem makes for a convenient argument for the different players in the mobile value chain to get what they want: it is a nice problem for everyone to have. For service provider side, it is the key to more frequency spectrum which further enhances increases their position in the market and consequently their value.  For solution vendors it gives them the opportunity to raise money, fund development projects and present forecasts for high revenues. For regulators it gives them the opportunity to sell spectrum and raise money. So everyone can benefit from the capacity problem, or so it seems. Read more of this post