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8 The Internet, or the cloud, has very high-speed interconnects (100Gbps or more), comparable with large freeways. But the exit lane, the pipe to our home called the "local loop" (or the "small cell" in wireless lingo), is usually 100Mbps at best, although 1Gbps fiber and 10Gbps Data Over Cable Service Interface Specification (DOCSIS®) 3.1 are starting to emerge. Then we have the option of a distributed Wi-Fi network in our house or building, for instance 802.11ac at 1Gbps or even a wired 10Gbps Ethernet cable. And finally, with the connection with the end node (the TV, game station, tablet, smart phone), we're again at something like 1Gbps, although this could even be 7Gbps if we use IEEE 802.11d (WiGig). Something is wrong with this. Where's the hierarchy? The high speed in the home is not served by the access to the home. We have freeways inside the house, but only a small street provides access to the house. And even inside the house, there is no real hierarchy. Take a look at this visual representation: WiGig Doesn't Help in This Scenario It's no surprise, then, that WiGig (IEEE 802.11ad) hasn't really taken off yet. Why build a higher multi-Gbps highway in your room, if it connects via a 1Gbps pipe to a 100 Mbps local loop, single lane road? It's also no surprise that in this context, the expectations for the tens of Gbps (IEEE 802.11ay) should not be too high. Higher data rates to the end nodes are great, but if the infrastructure does not support it, then what's the point? So, the fact that the step from IEEE 802.11ac to IEEE 802.11ax is a very moderate step in terms of data rate, and a step more focused on higher capacity in the home (multiple users at the same time) makes a lot of sense. But the real hurdle is getting more data to (and from) the home. Streaming and Bursting Affect Data Rates To complicate matters further, there are effects to consider from streaming and bursting. There is another factor also, that makes this all even more convoluted. There is a difference By Tony Testa, Director of Marketing for Qorvo's Wireless Connectivity Business Unit and Amelia Dalton, EEJournal.com EE Journal Chalk Talk Wireless Connectivity Front End Solutions When adding Wi-Fi to your design, the RF section poses some major challenges. With today's 2.4GHz and 5GHz spectrum getting more and more crowded, it takes some careful design to get the signals you want and filter out all the noise and interference. In this episode of Chalk Talk, Amelia Dalton chats with Tony Testa from Qorvo about high-performance RF front-ends for your next Wi-Fi design. between streaming and bursting. To stream a movie, you typically need a lot of continuing bandwidth for quite some time, say a continuous 20Mbps for high quality. That sounds quite doable with a 100Mbps pipe to your home. However, this 100Mbps has a somewhat statistical character. If everyone on the street is watching a movie, then the 100Mbps to your house quickly drops to significantly lower rates. Streaming a movie on a Saturday evening can be a challenging experience, as you are not the only one on the street (or in your small cell). It is no different than everyone in the house taking a shower at the same time, causing the pressure of the water system to drop. Burst is another statistical effect. You can compare it to someone opening all the taps in the home to get as much water flowing as possible. If someone tries to download a movie as fast as possible (to watch it later, for example), it causes a real burst of data consumption as the system tries to get as close as possible to the 100Mbps to one house, instantaneously. For a short time, this should be no problem. But of course, it is not sustainable, as the rest of the neighborhood would degrade quickly. From a statistical perspective, the chance that everyone on the street would try to download a movie at the same time is probably not that high, but the fact that bursts have an effect on the available bandwidth is clear. Out-of-Balance (100 Mb/s – 1 Gb/s – 7 Gb/s) ©2018 Qorvo, Inc. 1 Gb/s 7 Gb/s 7 Gb/s 7 Gb/s 100 Mb/s 100 Gb/s s

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