Shu (Marloon) Wang

Access Channel Enhancements for 1x Rel. F One Eighth Rate Access Probes for Smart Terminals Evolve Random Access Channels for IoT: I Introduction Evolve Random Access Channels for IoT: III Slotted ALOHA Models Evolving Random Access Channel for IoT: IV Dumb Access Probes and Smart Access Probes The IoT traffic characteristics are known to be substantially different from those of smartphones. Mobile networks were traditionally designed and optimized to transport connection-oriented traffic, where each connection is expected to be continuous with low latency. On the other hand, many IoT services are intended to be of low throughput, short duration and delay tolerant and characterized to be “connectionless.” As such while the existing mobile network operators start studying and optimizing their networks to accommodate the dynamics of growing IoT traffic, some companies start developing possible alternatives for IoT services. Comparison of UL Access Probe Designs for IoT ...

There are many parameters or specifications defined for quantifying the performance of a receiver design and implementation. Among them, the most notable includes the reference sensitivity power level (REFSENS) and the Total Isotropic Sensitivity (TIS), which are widely used for specify how sensitivity a receiver is. More sensitive a receiver is, less power it requires for maintaining a reliable communication and better performance it is believed to have. In general, REFSENS measures the performance of the receiver module with considering its down-converting performance, demodulation/decoding capability and self-generated interference/noise. Per 3GPP definition, REFSENS specifically denotes the minimum mean power applied to each applicable receive antenna port at which the throughput shall meet or exceed the requirements, which is not less than 95% of the maximum throughput of the specified reference measurement channel. See §7.3, Annexes A.2.2 (for FDD), A.2.3 (for TDD) and ...

Less than two years ago, I had a client who challenged me to improve the downlink sensitivity of a LTE receiver by 10 dB while maintaining its small form factor and battery life. At the beginning, I was so puzzled by her intention and tried hard to convince her that the mobile network in whole may not benefit much from such a single improvement. There are many other factors, e.g., battery life, downlink-uplink coupling, device cost, inter-cell interference and user capacity, to consider.  One year later, I was again amazed by the rapid rise of so many internet of things (IoT) systems each pretty much claiming a   ~170 dB link budget  and a  ~10 years battery life , in addition to its ultra-low device cost, enormous user capacity supporting tens-thousand devices per base station per channel user, and, did I mention this,  in a very noisy unlicensed ISM band.  goo.gl/pJb0KF .  Think about this,...

Airplay Music, A.K.A . AirTunes , is part of proprietary AirPlay protocol stack developed by Apple Inc. It is designed to use UDP  and RTSP network control protocol  for streaming audio over IP network.   So far, Airplay can only be used between airplay-enabled Apple devices and/or licensed third-party audio equipments.  As such, to AirPlay music from your iPhone to a Windows laptop, you need an AirPlay audio bridge like  Apple AirPort Express .  In this blog, I want to show you that you can do the same thing via a Bluetooth connection instead of an AirPlay audio bridge.  And it, indeed, is very simple. Most likely your Windows computer comes with a Broadcom Bluetooth chipset.  You can confirm this through the device management application of Windows.  If this is the case, go to Broadcom Bluetooth Software Download  and download updated Bluetooth for Windows software.   After install the updated Bluetooth software, you sh...

Access Channel Enhancements for 1x Rel. F One Eighth Rate Access Probes for Smart Terminals Evolve Random Access Channels for IoT: I Introduction Evolve Random Access Channels for IoT: III Slotted ALOHA Models During the discussion of evolving access channels for machine-to-machine (M2M) communication liked services, two major requirements are defined. As stated by 3GPP2 system requirement document, one is "[a]n M2M service shall not impact any ... existing applications and services that are currently being supported". The other one is "[t]he scalability of M2M Device deployment shall be supported ...to allow flexible M2M Device and service deployment scenarios for large numbers of M2M Devices."  More details of these two requirements can be found in  3GPP2 Machine-to-Machine Communication System Requirements, S.R0146-0  and 3GPP M2M Service Requirements, ETSI TS 102-689 . Due to the nature of M2M traffic pattern and QoS requirement, recent studies find ou...

[ Hack Patriot Box Office for Watching Chinese Videos and TVs ] Figure 1.   Apple TV Apple TV (ATV) is a  multi-function set-top box  designed by Apple Inc. originally as a  networked media player  for streaming multimedia contents to a television or an external monitor.  Now, it seemingly evolves into a iPod Touch without a touch screen but with a relatively inexpensive MSRP price tag of $99.  (Indeed, if you have an old generation iPod Touch, you may think about mirroring or airplay it onto a television instead.)  On March 7, 2012, Apple Inc. released a  3rd generation ATV (ATV3)   that includes a 32 nm ARM Cortex-A9 Apple A5 SoC (the same process as used in a 5th generation iPod Touch, a new iPad 2 and an iPad Mini) and 512MB mobile DDR2 memory (the same amount of memory as used in an iPhone 4).  An ATV3 has a buit-in 6 W power supply with no cooling fan necessary.  Unfortunately, until now, there is no publ...

How to Improve Forward Link Positioning ... ? I. Introduction 1x HDP Enhancements Enhanced Location Based Services Support in cdma2000 Enhance Downlink Positioning in WiMAX/16m How Wide A Widband Channel Should Be? IEEE ICC 2008 Tutorial, Location Based Services for Mobiles Location Based Services for Mobiles: I. Introduction Hearability Issue Hearability of a forward-link positioning system usually is quantified by how many reference signals a terminal may utilize to make a positioning fix in a pre-defined positioning duration.  In theory, a terminal need measure parameters of only 4 different reference signals for a precise three-dimension fix.  However, more reference signals a terminal can use, more diversity benefits a terminal may use for a more accurate positioning fix. A hearability issue of a cellular positioning network generally is a dimension limitation issue.  It mostly is due to limitations of network geometry and network deployment. ...