130 likes | 134 Views
This document proposes combining the 60 GHz PHY with a secondary low-rate PHY operating under a single MAC, to achieve high cell capacity and 100% coverage for applications like high-data-rate video streaming.
E N D
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Protocol Integration of 60 GHz PHY] Date Submitted: [07 March, 2006] Source: [Eckhard Grass, K. Tittelbach-Helmrich, D. Dietterle, J.P. Ebert, R. Kraemer] Company [IHP] Address [Im Technologiepark, Frankfurt (Oder), D-15236, Germany] Voice:[+49 335 5625 731], FAX: [+49 335 5625 671], E-Mail:[grass@ihp-microelectronics.com] Re: [] Abstract: [Some applications, like high data rate video streaming require both, very high cell capacity and 100% coverage. Due to the propagation characteristics at 60 GHz, this 100 % coverage is difficult to achieve. Therefore, we propose to combine the 60 GHz PHY with a low rate PHY. This secondary PHY is used to supply those terminals which are temporarily not connected via the 60 GHz radio. Furthermore, it is proposed to operate both PHYs under a single MAC.] Purpose: [ This document proposes the combination of the 60 GHz PHY with a secondary low rate PHY operating under a single MAC] 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. Eckhard Grass, IHP
Protocol Integration of 60 GHz PHY Eckhard Grass, Klaus Tittelbach-Helmrich, Daniel Dietterle, Jean-Pierre Ebert, Rolf Kraemer (IHP) Eckhard Grass, IHP
Outline • Introduction • Application scenario • Proposed 60 GHz PHY integration technique • Possible secondary systems • Evaluation and conclusions Eckhard Grass, IHP
60 GHz OFDM PHY Parameters Turbo mode with doubled subcarrier spacing possible => data rates up to 2 Gbit/s Eckhard Grass, IHP
Frequency Allocation in 60 GHz Band To guarantee QoS for fixed Installations and protect investment: Bandwidth allocation to „user groups“ 57 GHz 58 GHz 61 GHz 63 GHz 64 GHz • Three main frequency sub-bands: • Mobile End User, • Fixed Networks, • Emergency Allocated to fixed installations (Wire replacement, Train, Bus...) Allocated to mobile end user (Commodity products, Mobile,...) Emergency (like 11.p) 57 GHz 64 GHz 4 GHz 8x500 MHz channels 2 GHz 4x500 MHz channels 1 GHz 2x500 MHz channels Eckhard Grass, IHP
Scenario: Video Supply in Train • Combination of two Radios needed to achieve 100 % coverage: • High rate (60 GHz) system and secondary low data (~ 50 MHz) rate for video supply • ‘Data Shower’: 60 GHz only required for downlink • ‘Filling Gaps’:The secondary system covers only the gaps left by 60 GHz PHY • Secondary system can also be used as return/control/management channel Example Eckhard Grass, IHP
MAC Integration of 60 GHz PHY (I) • Problem: • Using a 60 GHz downlink, 100% coverage in a dynamic environment is hard to achieve (shading due to people moving about) • Approach: • Use a secondary low data rate bidirectional system in parallel with 60 GHz downlink for video supply in dense areas (bus, train, waiting areas, …) • Requirements • Deliver majority of the downlink data via 60 GHz link (available bandwidth) • Simple interface of the combined 60 GHz / low rate system with higher layers • Management and link information via low rate system • Tight coupling of low rate with 60 GHz system for fast selection of PHY • Automatic selection of ‚best‘ PHY Eckhard Grass, IHP
MAC Integration of 60 GHz PHY (II) 2.16 Gbit/s. . . . 1.08 Gbit/s . . . 120 Mbit/s 55 Mbit/s 44 Mbit/s 33 Mbit/s 22 Mbit/s 11 Mbit/s Application TCP Data rates of 60 GHz PHY IP MAC PHY- Select Data rates of 802.15-3 PHY (example for low rate PHY) 60 GHz PHY low rate PHY Eckhard Grass, IHP
MAC Integration of 60 GHz PHY (III) • Proposed Solution: • Treat the 60 GHz link as higher data rates within a low data rate protocol • Similar to IEEE 802.11 b/g except: • One MAC with two PHY which can operate in parallel • Two completely different carrier frequencies • Completely different data rates • Management/control information (authentication, association, join, acknowledgements, …) are always transmitted via low data rate PHY • At the beginning, data in downlink is always transmitted via 60 GHz PHY • If no connectivity to a certain terminal in 60 GHz downlink: Reduce data rate until low data rate PHY is selected; • If low data rate PHY is selected, send data via 60 GHz link in parallel for polling 60 GHz link; this doesn’t cost any valuable low data rate resources • If 60 GHz connection stable again: Signal to AP to stop low rate data transmission in downlink. Eckhard Grass, IHP
Possible Low Rate Systems • Low rate UWB (IEEE 802.15.4a) => 3 – 10 GHz (impulse radio) => 27 (54) Mbit/s ?? • IEEE 802.15.3-2003 • 868- 915-MHz and 2.4-GHz PHYs • 55 Mbit/s ?? • High rate OFDM-UWB (IEEE 802.15.3a or ECMA) => 3 – 10 GHz (Wideband OFDM) => 480 Mbit/s ?? • IEEE 802.11n MIMO systems: => 5 GHz; (MIMO – OFDM) => 600 Mbit/s ?? Eckhard Grass, IHP
Evaluation of Combined MAC • Disadvantages: • Fast MAC processor required (->anyway at 60 GHz) • TX and RX buffers needed to allow parallel transmission via 60 GHz and low rate PHYs • No redundancy in up-link • If low rate channel is blocked by other systems, there is no connection possible at 60 GHz either • Very different data rates may require different MAC parameters • Not simulated / tested yet • Advantages: • Simple and single Interface to upper layers • Integrated selection of data rate • Small extension to existing MAC (PHY selection layer) • Fast and automatic selection of PHY • Parallel transmission in down-link possible • Redundancy in down-link • Same principle can work for bidirectional transmission • Same principle can work with different low rate PHYs Eckhard Grass, IHP
Conclusions • 60 GHz systems can support massive data rates; However, 100% coverage for certain applications is difficult to achieve • Combination with secondary low rate system can provide both, high data rates, and 100% coverage • A possible scenario is to use the 60 GHz PHY for the downlink only, and to transmit all control information via the low rate PHY • Controlling the 60 GHz and low rate PHYs by a single MAC can simplify the system design • Detailed investigation of the proposed combination of PHY layers is required Eckhard Grass, IHP
Acknowledgements • BMBF (Federal Ministry of Education and Research – Germany) for funding the WIGWAM Project (http://www.wigwam-project.com/) • WIGWAM Team at IHP: Maxim Piz, Klaus Schmalz, Yaoming Sun, Srdjan Glisic, Milos Krstic, Klaus Tittelbach, Wolfgang Winkler • WIGWAM Consortium - in Particular Project Coordinators:Gerhard Fettweis and Peter Zillmann (TU Dresden)(http://www.wigwam-project.com/) Eckhard Grass, IHP