Showing posts with label 4G. Show all posts
Showing posts with label 4G. Show all posts

Wednesday, October 17, 2012

4G: LTE/LTE-Advanced for Mobile Broadband Review

4G: LTE / LTE-Advanced for Mobile Broadband
(Image via Amazon aStore)
The book starts with standards and basic technologies - the role of the International Telecommunications Union (ITU)in standards, multiplexing (TDMA, FDMA, OFDM), transmission (DFT-Spread OFDM), modulation (QPSK, 16QAM, 64QAM), multi-antenna technologies. The discussion of LTE starts in detail in Chapter 7. Chapter 8 shows the radio network architecture, with a useful downlink protocol architecture diagram (Figure 8.4). This book focuses on the Radio Access Network. For the packet core network architecture (Evolved Packet Core - EPC), the reader is referred to SAE and the Evolved Packet Core: Driving the Mobile Broadband Revolution. LTE has different implementations for the wide range of devices and environments that it supports. Spectrum flexibility, a key feature of LTE in a spectrum starved world, is discussed in detail. There are also multiple transmission modes, described in support of the different types of antenna systems in Chapter 10.

The signaling for the downlink in Chapter 10 and Chapter 11, which focuses on the physical layer uplink channel processing and transmission, is described in detail. Chapter 12 focuses on retransmission which is a two-level structure using the MAC and RLC network layers. Chapter 13 looks at the power control and scheduling, then goes into how inter-cell interference is handled. It analyzes both pico cells and macro cells. Chapter 14 discusses how a device finds the network cells. It also discusses how a network can page a device to wake it up.

Chapter 15 describes broadcasting using Multimedia Broadcast Multicast Services (MBMS). The book notes the benefits to the device - battery savings - as well as to the network - reduced load. Chapter 16 gets into using the backhaul network to repeat signals - with or without decoding and recoding. Chapter 17 gets into available spectrum and has useful tables detailing current allocated spectrum in major markets. Wireless performance is highly dependent on terrain, buildings and impediments to radio signals. The book quotes 3GPP (Third Generation Partnership Project) base station and device output power for test environments - indoor, microcellular, urban base coverage and rural high speed coverage. The chapter also looks at the cell spectral efficiency.

Chapter 19 could almost be at the beginning as it compares LTE to alternative technologies. The book ends with a list of references. The book needs challenging questions and examples at the end of each chapter if it is to be used as a textbook. It also lacks a glossary of acronyms, however given the number of websites that provide lists this is not a serious omission.

The book is ideal for product managers, marketing managers and engineers in telecom equipment vendors or service provider companies who want a general understanding of LTE and how the different protocol layers fit together.

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Saturday, September 22, 2012

Samsung Galaxy S III 4G Android Phone Review

Samsung GALAXY S III (3)
I upgraded from a Motorola Droid 2 to the S3 and am completely satisfied with the S3. The large 4.8 inch AMOLED screen is beautiful and it fits perfectly in my palm. The resolution is exceptional, words cannot describe it.

I can use one hand/thumb to do most tasks and feel that the S3 could have been even larger without compromising convenience. I'd say a 5.5 inch screen would be the highest I'd go. The problem arises when using a holster. As a guy, I have a hard time just putting a phone in my pocket because I use my pockets for keys, pens, and my wallet, which can easily scratch/damage the phone when moving around. I don't always have a backpack or pack on hand, so that leaves me with a holster as the only logical method of carrying a phone. The Otterbox Defender has been by far the best case/holster I've found for the S3. Unfortunately, with the Defender, the S3 feels like I am hauling around a Texas Instruments graphing calculator on my belt. When calling someone, it's like I am calling in an airstrike. However, it is never uncomfortable to use. Even for such a large phone, I find myself not getting fatigued when making long phone calls. The audio quality during calls is exceptional and there are multiple equalizer/sound settings to improve the audio quality.

The T9 dialing is perfect - I never understood why my Droid 2 did not have this feature, but T9 is a time saver. The predictive text and swiping keyboard takes some getting used to at first, but it works fairly well for a built-in feature. The voice-to-text input isn't bad but there are some odd mistakes from time to time.

S-Voice is essentially Samsung's version of Siri, although Siri started off as an independent app designed for the iPhone and Android before Apple took them over and squashed the Android project. S-Voice is tied into Wolfram Alpha, and I find that although it is innovative, it is more of a gimmick. I can find the weather info a lot faster using the browser/weather app and the 4G LTE network than waiting for "Galaxy" to answer my question.

S-beam is interesting at first, but a co-worker (who also bought a S3) and I played around with this and we both agree it is essentially a local peer-to-peer network not unlike Bluetooth or a WiFi-based LAN. It is definitely innovative, but I don't feel it is essential.

The battery life could be better from the rather large 2.1 Ah battery. I was able to get 3.5 days (3 days, 12 hours and change) out of 1 charge. My daily usage pattern is auto brightness, 4G LTE, and airplane mode at night, with occasional surfing/usage during the day.

The mechanical Home button feels antiquated and out of place. I never understood why Apple used this, and I don't understand its place on the S3. It should have been a capacitive soft key like the menu and back keys on the S3. However, Samsung decided to make the soft keys "disappear" when not backlit, which is annoying. I am used to the Droid 2 where the soft keys were all etched into the display. The LED indicator on the S3 is also subdued and is only visible when it is illuminated. When fully charged, the LED will glow green but it is not strong enough to bother me when I am sleeping. It's a soft and subdued glow. When there is new email or a new text message, it flashes blue. When it is charging, it glows red.

The front and rear camera quality is exceptional. The front is a 1.9 MP camera that produces beautiful video during video conferences. The rear camera is the same camera they used on the iPhone 4S, and has burst mode and truly has zero lag. The flash is extremely bright and has a white color (close to 6000K or so) unlike my Droid 2 which was more yellow (about 3000K-4000K). The picture quality is really good, especially for a smartphone.

The Samsung S3 does not come with a micro SDHC card, so I purchased a Sandisk 32GB Class 10 micro SDHC card. Android 4.0.4 (Ice Cream Sandwich) operates differently from Gingerbread with the respect that all apps are stored on the phone's internal memory. That means all of the apps are run off the 16GB "SDcard" and not your external SD card. When I inserted the 32GB Sandisk micro SD card, a new folder popped up "ExtSDCard" which points to the actual external SD card. Luckily, the camera app will notice this and ask to store all photos/videos on the external SD card. The apps and associated files remain on the 16GB internal memory.

I ran the AnTuTu benchmark and got a score of 6885, which was run without power saver and the dual-core CPU was at 1512 MHz. When I activated Power Saver, my score was 5221 with a CPU speed of 1026 MHz. As one can see, the score with Power Saver is still very respectable. The external SD card read speed was greater than 50 MB/s, while the write speed was about 29.7 MB/s max. The S3 has a lot of processing power and it is putting my Core 2 Duo laptop to shame when accessing YouTube videos and opening files. The S3 menu interface just glides seamlessly with zero hiccups or delays.

Verizon's network is the main reason why I stayed with Verizon instead of hopping to Sprint. Even though Sprint offers unlimited data (until they throttle you above 2.5 GB if you do this consistently), their network coverage is poor and their network speeds are abysmally slow. Verizon's coverage is the best in the US, and I can still get a signal 16 nautical miles off the shore of South Carolina. Verizon's 4G LTE coverage is also very good in my area, with my download speeds ranging in the 20 Mbps, and upload speeds in the 14-16 Mbps range. I get these speeds consistently using Speed Test, which means that the 4G LTE network in my area is competing against my Comcast cable internet connection. My biggest complaint about Verizon is how they forced me off the Unlimited Data plan - the alternative was to pay $600 for a new phone to keep the plan. However, from a business perspective, I understand and agree with Verizon's decision. Bandwidth is expensive and with cable internet speeds in the palm of your hand on a machine that rivals laptops, data usage goes quickly out of hand.

My friend at work had some issues with her S3, but she purchased her S3 the day it came out on Verizon based on my recommendation because her Droid 2 was really messed up. She experienced random ghost calls with the S3, and the data network kept switching between 3G and 4G LTE. I don't recall her experiencing the "No Sim card" issue that others saw with their S3. I've been using my S3 for almost 2 weeks and have not experienced any of the above problems. I solved the constant WiFi notification by deleting my known WiFi networks on the phone. The negative aspect is that I cannot use WiFi to save on my data consumption with this method. I've heard theories about the No Sim error and the ghost calls, some of them recommend pulling out the battery and Sim card, but others have recommended using Airplane mode. Since I use Airplane mode on a nightly basis, this might be the method of resolving some of the network problems.

Overall: 5/5 stars. I purchased the S3 because I hate iTunes with a passion. The verdict from the Apple/Samsung case also affirmed my feelings about how Apple conducts business. I really like my S3 phone and like the Android operating system. Samsung really knows how to design their products which includes televisions, refrigerators, and other devices.

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