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Airplanes and Rockets:
Feds: It’s Tough To Get Agencies to Share Spectrum
The White House is trying to figure out how to get government agencies to give up their cherished spectrum to commercial users in order to free up the 500 MHz it has promised for use by wireless broadband. Several proposed ideas include creating a fund from the proceeds of spectrum auctions to help agencies cover the costs of moving, charging agencies for their use of spectrum, and allowing them to lease spectrum on a short-term basis.
Another idea is to create one gigahertz of shared spectrum that could be used by both commercial and federal government users while also creating a tiered approach that gives the federal government priority access but also allows licensed commercial organizations to use it.
The Latest Killer App for NFC: Fear
Near Field Communications (NFC) is always seemed like it needed a big push to get started, and how it has one: security. Visa and MasterCard are working feverishly to allow shoppers to pay at retail stores without pulling out their credit cards. Both companies just announced that they working with retailers and banks to incorporate better “contact-less” payment systems into their mobile apps.
In this first round of a rush to NFC it looks like Android will be the winner as one of its latest features called Host Card Emulation that allows personal information to be stored in the cloud rather than the phone, which the app then accesses at the point of sale. The Kit Kat (Version 4.4) of Android offers this feature in many Android phones have it. The iPhone 5S does not have it. The card number is stored in encrypted form on the phone and can be disabled remotely if the phone is lost or stolen.
|The Crucial Role of Carrier Aggregation in LTE-Advanced
By Sam Benzacar
The issue of spectrum fragmentation has long been a thorn in the side of wireless carriers, as there is no contiguous spectrum available to provide the increased bandwidth required to deliver the high-speed data communications required for LTE-Advanced.
Fortunately, the standard itself is solving this problem through carrier aggregation, which allows carriers to combine a 20 MHz of spectrum with 20 MHz and another and so forth up to five segments. Collectively they produce a bandwidth of 100 MHz, which is what LTE-Advanced will require to deliver its blazing theoretical data rate of almost 3.3 Gb/s using 8x8 MIMO.
Much has been written about carrier aggregation from a technical perspective, but at the “50,000 foot level” the benefits of this technique cannot be overstated. There is obviously no practical way to reallocate spectrum allocations throughout the world, and no carrier has 100 MHz of contiguous bandwidth, so without carrier aggregation it’s safe to say that LTE-Advanced would be extremely difficult if not impossible to achieve.
That’s not to say that the other technologies required to realize 3GPP Release 10 that delineates LTE-Advanced, are less important or even trivial as they are neither. Release 10 is enormously complex and relies on various types and levels of MIMO, beamforming, a new feature called Coordinated Multipoint (CoMP) that increases performance at cell edges and provides greater support of heterogeneous networks (that is, macro, pico, and femto cells), along with comprehensive software, high-speed processing and analog-to-digital and digital-to-analog conversion, among other things.
However, the ability to combine 20-MHz slices of spectrum whether near or far away in frequency provides the key to unlocking the performance of LTE-Advanced. From an RF perspective, implementing this do standard appears to be somewhat less daunting, requiring changes to transceiver design, as well as modifications to base stations and widespread use of small cells.
And of course, filters will continue to play a key role in keeping interference in check, although in some wideband transceiver architectures this filtering will perform digitally.
In short, carrier aggregation and the other technologies that will make LTE-Advanced the reality are well along in development. In fact standards groups are already focusing on Release 11, which rather than increasing data rates promises to deliver better overall performance.
Proposed enhancements include more streamlined carrier aggregation and CoMP, a new control channel, better inter-cell interference coordination and avoidance, reduced power consumption for user devices and the network, support for machine to machine communications, and other tweaks.
Anatech Electronics has been solving interference problems in wireless systems since the first cellular systems appeared, and we can help you solve yours today. So please give us a call at (973) 772-4242 or send us an email to firstname.lastname@example.org.
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