<month year> doc.: IEEE 802.15-04-0622-00-004a Nov 2005 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Limitations of the channel and potential problems to the system design] Date Submitted: [13 Nov, 2005] Source: [Su-Khiong Yong] Company [Samsung Advanced Institute of Technology (SAIT)] Address [RF Technology Group, Comm. & Networking Lab., P. O. Box 111, Suwon 440-600, Korea] Voice:[+82-31-280-9581], FAX: [+82-31-280-9555], E-Mail: [su.khiong.yong@samsung.com] Re : [IEEE 802.15.3c Channel modeling] Abstract: [Limitations of the channel and potential problems to the system design] Purpose:[This document discusses the propagation issues and parameters for IEEE 802.15.3c] Notice :This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. Su-Khiong Yong, Samsung-SAIT <author>, <company>

Limitations of the Channel and Potential Problems to the System Design <month year> doc.: IEEE 802.15-04-0622-00-004a Nov 2005 Limitations of the Channel and Potential Problems to the System Design Su-Khiong Yong Samsung Advanced Institute of Technology (SAIT), Korea Su-Khiong Yong, Samsung-SAIT <author>, <company>

Outline Objectives Current Status / View Limitations of the Model <month year> doc.: IEEE 802.15-04-0622-00-004a Nov 2005 Outline Objectives Current Status / View Limitations of the Model The Potential Problems Conclusions Su-Khiong Yong, Samsung-SAIT <author>, <company>

<month year> doc.: IEEE 802.15-04-0622-00-004a Nov 2005 Objectives To response to the call for selecting a “simplified model” during the Garden Grove meeting. To discuss what are the potential problems that could be generated. Su-Khiong Yong, Samsung-SAIT <author>, <company>

Nov 2005 Current View Due to the tight time line, there was a suggestion to change the modeling plan to a “simplified” version. The below channel models were described IBM data, journal papers, etc (call model A) Channel Model as a function of antenna gain (IBM or Some Additional Measurement) (call model B) Channel model that can meet 03/06 deadline with AoA (Delay in CFP) NICTA, UMass (call model C) So what are the potential problems associated with this model B? Su-Khiong Yong, Samsung-SAIT

What Are the Limitations of Model B? Nov 2005 What Are the Limitations of Model B? What does it mean channel model as a function of antenna gain? To have that model, Perform endless measurements with different antenna setups Resort to a double directional channel measurement and modeling So, the model B mentioned will only valid for that specific antenna setup. You can’t do anything about it, so it is not a function of antenna gain rather it is valid for a fixed value of the antenna gain of the specific antenna used. This model is not sufficiently generic. Su-Khiong Yong, Samsung-SAIT

Nov 2005 What Are the Problems? At 60GHz, specular reflections are the primary mode of propagation, while diffuse reflections and diffraction do not contribute significantly to the received power. Also, we know that at 60GHz, signals undergo severe path loss and transmission loss due to walls, partitions, furniture etc. Su-Khiong Yong, Samsung-SAIT

What Are the Problems (cont)? Nov 2005 What Are the Problems (cont)? Using the model B with a specific antenna setup, what will happen if the antenna in one end link is misaligned in LOS condition? This situation is common as user does not suppose to handle where to direct the antenna. Our target is not only for the scenario where the Tx and Rx are pointed to each other and it is also hard to guarantee the LOS condition in indoor environment e.g. typical office. Su-Khiong Yong, Samsung-SAIT

What Are the Problems (cont)? Nov 2005 What Are the Problems (cont)? So we will have no idea what will happen to the channel characteristics if the antennas are misaligned as paths might arrive from other directions with much higher power Su-Khiong Yong, Samsung-SAIT

Nov 2005 Perfect Alignment The radiation pattern of each antenna is pointed towards the AOA or AOD of the most significant path M. Williamson et. al, “Investigating the Effects of antenna directivity on wireless indoor communications at 60GHz, IEEE PIMRC 97 Su-Khiong Yong, Samsung-SAIT

Misalignment Nov 2005 30o Tx and Omni Rx M. Williamson et. al, “Investigating the Effects of antenna directivity on wireless indoor communications at 60GHz, IEEE PIMRC 97 Su-Khiong Yong, Samsung-SAIT

Effect of Rotating the Antenna on the RMS Delay Spread Nov 2005 Effect of Rotating the Antenna on the RMS Delay Spread LOS condition is at 72o M. Williamson et. al, “Investigating the Effects of antenna directivity on wireless indoor communications at 60GHz, IEEE PIMRC 97 Su-Khiong Yong, Samsung-SAIT

Effect of Rotating the Antenna on the K-Factor Nov 2005 Effect of Rotating the Antenna on the K-Factor M. Williamson et. al, “Investigating the Effects of antenna directivity on wireless indoor communications at 60GHz, IEEE PIMRC 97 Su-Khiong Yong, Samsung-SAIT

This may happen in other angles which will need to know. Nov 2005 But in NLOS we could see that it is not necessary for the direct pointing angle of the Tx-Rx will give the lowest RMS delay spread and highest K-factor. This may happen in other angles which will need to know. Su-Khiong Yong, Samsung-SAIT

Nov 2005 Conclusions We need to properly characterize the channel before we can design a reliable system It seems that channel model B will not be able to address some of the important criteria for performance evaluation. The directional information (at least in one link) is a must. Su-Khiong Yong, Samsung-SAIT