WiWavelength

We left off previously with a 5 MHz LTE downlink divided into 300 OFDM subcarriers, which were grouped by 12 into 25 RBs. Technically speaking, a RB also carries a time division element. So, let us explore that next. Starting with a single second, an LTE downlink is divided into 100 frames, each 10 ms in duration. Each frame is divided into 10 subframes, each 1 ms in duration. And each subframe is divided into two slots. Finally, each slot is divided into six or seven sequential RF symbols, but these RF symbols cannot be individually scheduled. So, from a scheduling standpoint, the slot is the minimum unit of time. As a result, a single RB assigned to an active user is more accurately defined as that RB assigned for one slot. In other words, the minimum allocation that an active user can receive is 12 subcarriers assigned for 0.5 ms. If we were to assume that each active user requires a constant flow of data, hence each active user must be assigned at least one slot per frame, then the theoretical maximum number of active users that a 5 MHz downlink could simultaneously support per sector would be 500 (e.g. 25 RBs per 5 MHz × 20 slots per frame = 500). AJ

An LTE downlink is comprised of Orthogonal Frequency Division Multiplex (OFDM) subcarriers. This is the frequency division aspect of LTE. A 5 MHz downlink contains 300 subcarriers, which are organized into groups of 12 called Resource Blocks (RB). Thus, a 5 MHz downlink also contains 25 RBs. Each active user is assigned, at minimum, one RB. So, from a frequency division standpoint, a 5 MHz downlink can support up to 25 active users per sector. Now, LTE uses not only frequency division but also time division. Coming up later, I will detail how each RB can be allocated to different active users on a time division basis, thereby multiplying the maximum possible number of active users to >25 per sector. AJ

Ben, you are from Phoenix. You are not allowed in this thread until next year. AJ

Well, no one should be surprised by the inclusion of a physical keyboard. Once the "Q" appendage was attached, historical Motorola nomenclature indicated that this handset was going to have a physical keyboard in some way, shape, or form. AJ

Antenna gain? If so, no, not in this filing. Some authorizations include it, but many do not. The proof is in the pudding, so the FCC cares about conducted power and radiated power. As long as the device stays within those power restrictions, the antenna gain can be anything. AJ

My technical rundown of the presumed Photon Q's FCC filing just went live on The Wall. http://s4gru.com/index.php?/blog/1/entry-294-fire-photon-torpedoes-motorola-photon-q-hits-the-fcc-oet/ AJ

by Andrew J. Shepherd Sprint 4G Rollout Updates Tuesday, July 3, 2012 - 2:54 PM MDT S4GRU continues with the third in a series of short articles on the FCC OET (Office of Engineering and Technology) authorization filings for "tentpole" devices headed to Sprint's upcoming Network Vision enhanced LTE overlay. Over the past few months, we have brought you the scoop on the FCC authorizations for the HTC EVO 4G LTE and the Samsung Galaxy S3. Today, the Motorola model number XT897 hits the FCC OET database with FCC ID IHDT56NL2, and we expect this mystery handset ultimately to be the Photon Q. Without further ado, here is the RF rundown: CDMA1X + EV-DO band classes 0, 1, 10 (i.e. CDMA1X + EV-DO 850/1900/800) LTE band 25 (i.e. LTE 1900; PCS A-G blocks) LTE 5 MHz and 10 MHz carrier bandwidths world phone international roaming capability 802.11b/g/n Wi-Fi; max MCS index 7 (i.e. 20 MHz channel, 400 ns guard interval, single spatial channel) SVDO and SVLTE support, including SVDO or SVLTE and simultaneous Wi-Fi tether Maximum RF ERP/EIRP: 22.45 dBm (CDMA1X 850), 19.89 dBm (EV-DO 850), 27.12 dBm (CDMA1X 1900), 24.03 dBm (EV-DO 1900), 21.72 dBm (CDMA1X 800), 19.33 dBm (EV-DO 800), 25.22 dBm (LTE 1900) NFC capability Antenna locations: CDMA1X bottom, EV-DO/LTE top, Wi-Fi/Bluetooth bottom The Photon Q's FCC filing makes mention of world phone international roaming capability, albeit latent inside the handset. Presumably, it will include at least GSM 900/1800 and W-CDMA 900/2100+1900 (a la the international roaming capabilities announced to be unlocked in several VZW handsets). But, before anyone asks, do not expect any LTE international roaming capability. RF uplink output looks to be healthy. It is generally a bit higher than what we have seen recently from the EVO LTE and Galaxy S3. However, unlike the EVO LTE and Galaxy S3, the Photon Q lacks 802.11a/n Wi-Fi 5 GHz band capability. The filing indicates that the hardware is present, but 5 GHz operation is locked out. So, the Photon Q will be stuck in the increasingly overcrowded 2.4 GHz band. At this point, the LTE UE category remains unknown. Recent Motorola RAZR LTE handsets on VZW have used Moto's own Wrigley LTE baseband chipset, which has limited those devices to LTE UE category 2. We hope that the Photon Q will utilize the Qualcomm MSM8960 as a single chipset modem, as that should enable UE category 3. Perhaps the most interesting and potentially controversial aspect of the Photon Q's FCC authorization is the inclusion of two references to the Motorola Admiral, a front facing QWERTY handset currently available on Sprint. One reference cites the Admiral as a "similar transmitter;" the other reference flat out calls the Photon Q the Admiral. Thus, while some sites have leaked photos of what purports to be the Photon Q in the expected QWERTY slider design, we leave open the possibility, however modest, that the Photon Q may arrive as an LTE refreshed Admiral clone with a front facing QWERTY keyboard. Sources: FCC

To add another thought on this scenario, about 10 years ago, a prospective wireless licensee floated a plan to reuse for its downlink the DSS frequencies assigned to DirecTV and Dish Network. The licensee wanted to deploy only south facing antennas that would, presumably, not interfere with reception for DBS dishes because the dishes all would be similarly facing south. In other words, the cell sites would transmit only south and those transmissions would be blocked by the backs of the DBS dishes. Of course, multipath reflections (from buildings, trucks, and, poetically enough, the backs of those DBS dishes) would have bounced parts of that signal back north in a heartbeat. I have no idea how this plan ever made it past the sketch on a napkin stage. It makes the LightSquared proposal seem incredibly well engineered, by comparison. AJ

That is partly right. The SMR 800 MHz band in Canada is used for iDEN (Telus Mike), but it is also used for public safety. Regardless, those are narrowband operations (25 kHz channelization). So, as Robert adroitly indicates in his response above, the US and Canada coordinate usage of those narrowband channels. Along the border, the US gets to use one set of channels, while Canada gets to use a different set, etc. Now that Sprint intends to shut down iDEN and deploy wideband operations (CDMA1X and LTE) in its SMR 800 MHz spectrum, however, channel coordination becomes difficult, even downright impossible because wideband operations occupy so much greater bandwidth. And that is why Sprint may be unable to deploy LTE 800 in some markets near the Canadian border. AJ

Prior to PCS Vision, Sprint's cdmaOne circuit switched data service was called Wireless Web. Circa 2000-2001, when VZW was still getting its act together following the merger that formed it and Sprint was the only carrier to offer seamless wireless data service in all major markets, Wireless Web was kick ass. AJ

Either some birds have taken roost between those antennas or that tower is in need of a Brazilian wax. AJ

"Whoa, man, wow. That's so intense." I feel quite certain that guy in the video could tell you where you could get some weed. AJ

...even my massive collection of albino midget amputee pr0n? I cannot pass the time in the checkout line at the grocery store without that. AJ

Sprint unfortunately rejected my idea to brand EV-DO as Double Vision. Imagine the catchy ad campaign... AJ

...and reflect off of mountains and buildings back into Canada. It is not that simple. It is called multipath. Look into it. AJ

Unless you must have the smaller form factor, the Nexus 7 tablet absolutely destroys the Galaxy Player 5.0 now in both specs and value. AJ

It did not. PCS Vision and 1X went hand in hand. No 1X, no Vision. AJ

Nope, it is worse than that. The Uproar is a cdmaOne handset. It was released in 2001, roughly a year before Sprint launched CDMA2000, so it is not 1X capable. AJ

I do not know what happened, but my eHERPIES disappeared for about two days. So, I made the most of it and went around having lots of phone sex. The eHERPIES are back now, though. AJ

Guys, these are to be raw RF tests, not speed tests. Many of the handsets likely will not even be activated. AJ

Nope. eHRPD is a core network enhancement. It has no effect on the airlink, which remains EV-DO Rev A. AJ

In order to get reasonably valid results, I recommend a strict testing protocol: all handsets be set to a single mode (e.g. 1X only or EV-DO only) all handsets be set to the same sampling interval (preferably 5 sec) all handsets be confirmed on the same RF channel and PN offset all readings be taken over a significantly long period (probably 2 min) and averaged AJ

...or should it be the 38 Special award? AJ

The device with the highest signal level while being held wins the Fleetwood Mac award. http://www.youtube.com/watch?v=LzwO4iW3P0Q AJ

Robert may have to adopt Buddhism in order to manage all of these handset RF tests. AJ