Integrated Programmable Communications Inc November 2001 doc IEEE

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Project: IEEE P 802. 15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: A Wise AFH Solution for WPAN Date Submitted: November 1, 2001 Source: YC Maa, HK Chen, Shawn Liu and KC Chen Company: Integrated Programmable Communications, Inc. Address: Taiwan Laboratories Address: P. O. Box 24 -226, Hsinchu, Taiwan 300 TEL +886 3 516 5106, FAX: +886 3 516 5108, E-Mail: {ycmaa, hkchen, shawnliu, kc}@inprocomm. com Re: [IEEE 802. 15 -00/367 r 1, IEEE 802. 15 -01/082 r 1, IEEE 802. 15 -01/246 r 1, IEEE 802. 15 -01/252 r 0, IEEE 802. 15 -01/366 r 1, IEEE 802. 15 -01/382 r 0, IEEE 802. 15 -01/385 r 0, IEEE 802. 15 -01/386 r 0, IEEE 802. 1501/443 r 0, IEEE 802. 15 -01/471 r 0, IEEE 802. 15 -01/491 r 0] Abstract: This document presents a wise AFH scheme for 802. 15 TG 2 Coexistence Mechanism. Purpose: Submission to TG 2 for AFH draft consideration. Notice: This document has been prepared to assist the IEEE P 802. 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 P 802. 15. Submission Slide 1 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 A Wise AFH Solution for WPAN KC Chen, YC Maa, HK Chen, and Shawn Liu Integrated Programmable Communications, Inc. Submission Slide 2 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Outline q. Review on Channel Naming q. Considerations üRegulation Change Effect üImplementation and Complexity q. Conclusion and Recommendation q. Appendix: Complexity Estimation for AFH Submission Slide 3 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Review on Channel Naming Submission Slide 4 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Review of AFH Channel Naming q Channels are classified into 3 groups: (dynamic classification) ü ü Usable channel set SU: uninterfered or “good” channels (size = NU) Kept channel set SK: interfered channels kept for AFH (size = NK) Removed channel set SR : interfered channels left out in AFH (size = NR) NU + NK + NR = 79 q Define Nmin to be the minimum number of channels that a Bluetooth device must hop over. q Usable and Kept need to be considered, based on Nmin, NU: ü Nmin NU: only use usable channels in the hopping sequence ü Nmin > NU: require kept channels in addition to usable channels in the new hopping sequence, where kept channels NK = Nmin–NU q When kept channels are required, both “partition sequence” and “mapping” mechanisms are executed. ü Mode L uses usable and “fill-in” channels blindly q When kept channels are not required, only “mapping” mechanism is executed. Submission Slide 5 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Considerations Submission Slide 6 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Worldwide Regulations q United States (FCC): ü Currently FH devices must hop over a minimum of 75 channels. ü NPRM suggests a new minimum hopset of 15 channels. • Two other proposed rule changes on the same NPRM – DSSS processing gain – new Digital Transmission Technologies (DTS) • Decision for ruling may drag on q Europe (ETSI): ü FH devices must hop over a minimum of 20 channels, • France allows operation at 2. 4465 -2. 4835 GHz, a total of 37 MHz, but Bluetooth devices only use 23 channels. • Spain recently increased to a total of 79 channels q Japan: ü No restriction on the minimum number of channels today. q Asia (especially China) ü Rule change usually falls behind US or Europe by 2+ years. Submission Slide 7 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Mode H & L under FCC/Global Regulation q Mode H works under current FCC regulation ü Works for all Bluetooth devices (type 1, 2, 3) today ü Will always work under FCC regulation, regardless what Nmin may be. q Mode L may not always work under current FCC ü Does not work for type 1 & 2 Bluetooth devices (high power) ü May work only for type 3 device (low power constraints) ü May work better under future FCC regulation (if Nmin= 15) q Mode H always complies with current and future FCC/global regulation, while mode L does not q As the ISM band gets more crowded, the benefit of Mode H is more significant. Submission Slide 8 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Important Usage Scenarios: Three 802. 11 b APs (01/443 r 0) q Agreed by all, including TI and Bandspeed, as very important scenario in Mar 01 meeting. ü Three collocated access points (on channel 1, 6, 11) will be common in the enterprise environment. • The three networks will occupy a total (30 -d. B) bandwidth of 66 MHz, which implies that these networks occupy 67 Bluetooth channels. • only 12 Bluetooth channels are free of interference (NU = 12). • if Nmin = 15, then we are forced to use 3 kept channels in the adapted hopping sequence. • if Nmin = 20 then we are forced to use 8 kept channels in the adapted hopping sequence. ü Kept channels must be used intelligently, otherwise • Higher packet error rate, which leads to unacceptable voice quality • Lower throughput. Submission Slide 9 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Effects of the NPRM (01/443 r 0) q Proposed rules in NPRM are less strict than the current rules. ü NPRM was issued to allow new modulation schemes, such as PBCC-22 and OFDM, into the 2. 4 GHz band. ü An OFDM signal has a larger bandwidth than the current IEEE 802. 11 b signals. ü Spectral mask 20 d. B-Bandwidth: 22 MHz ü Spectral mask 28 d. B-Bandwidth: 40 MHz q Thus, spectrum free of interference will become even more difficult to find! Submission Slide 10 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Regulation Change Effect q New NPRM seems to justify Mode L. q Yet new application scenarios, enabled by NPRM ü Booming enterprise WLAN deployments ü New technologies, such as OFDM, PBCC-22 will lead to a more crowded ISM band spectrum, which will not leave enough Usable channels for Mode L or FH schemes with small hopset! q Mode H is significantly more effective in a more crowded ISM band. Submission Slide 11 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Implementation and Complexity q Implementation ü One shot design vs. Incremental redesign • One-shot design – Design right at the first time – Works under any regulation • Incremental redesign – Occurs as regulation changes – Overwhelming effort and complexity at a great cost q Complexity ü Relative complexity • In % gates to a typical implementation • In % MIPS to a typical m. C processing power ü Much cheaper than the incremental redesign cost!! Submission Slide 12 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Complexity Estimates for mode H & L (01/471 r 0) q Examined: ü Mapping & Partition functions ü Software and hardware realizations q Left out: ü Channel classification algorithm ü Pseudo-random number generator q Assumption: ü The basic time unit for AFH mechanisms is one slot – 625 us. Submission Slide 13 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 AFH Complexity Estimation Summary q Hardware complexity ü mode H - 5. 1 K gates ü mode L - 3. 1 K gates • Difference of 2 k gates, or • 2% for a typical 100 K-gate Bluetooth design, or • 0. 4% for a typical 500 K-gate co-located Bluetooth/WLAN design q Software complexity ü mode H - 0. 19~0. 64 MIPS ü mode L - 0. 17 MIPS • up to 1. 18% more, based on a 40 -MIPS micro-controller q The added complexities are miniscule ü Compared to today’s HW & SW design overall complexity ü Compared to the overwhelming incremental-redesign costs q For details, please refer to Appendix Submission Slide 14 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Conclusion & Recommendation Submission Slide 15 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Conclusion and Recommendation (1) q NPRM leads to more crowded ISM band use ü Booming enterprise WLAN deployments & new technologies, such as OFDM, PBCC-22 ü Insufficient usable channels for mode L ü Mode H not only conforms to current and future FCC regulation, but also adapts to future ISM band wireless boom. q Only < 2% complexity added by Partition Sequence, a universal design ü spares a lot of re-design/re-spin cost and efforts. ü works all over the world. Submission Slide 16 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Conclusion and Recommendation (2) q. AFH merger proposal (01/382 r 0) and AFH draft (01/491 r 0)Wise AFH Solution for WPAN üTechnically, intelligent AFH Scheme üProduct-wise, deal with current and future market needs while avoiding re-design cost üIndustry-wise, a wise decision to harmonize AFH schemes in 802. 15 TG 2 and Bluetooth SIG Coexistence WG Submission Slide 17 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Appendix : Complexity Estimation for AFH Submission Slide 18 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Appendix: Complexity Estimation for AFH q Examined: ü Mapping & Partition functions ü Software and hardware realizations q Left out: ü Channel classification algorithm ü Pseudo-random number generator q Assumption: ü The basic time unit for AFH mechanisms is one slot – 625 us. Submission Slide 19 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Software Implementation Assumption(1) q Division/Mod operation ü A=B*Q+R, Q=floor(A/B), R = A mod B ü It can be implemented in software by long-division. Each iteration requires 8 operations: – – – Two shift operations One compare One conditional jump One subtraction, and one addition Two instructions for loop: one subtraction, and one conditional jump • Number of iterations required is equal to the width ( number of bits) of A, WA. • The total instruction cycles required is roughly 8* WA. Submission Slide 20 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Software Implementation Assumption(2) q Multiplication ü Many processors have special instruction for multiplication (C=A*B). ü If not, it can be implemented in software • Each iteration requires 5 operations: – Two shift operation – One conditional addition – Two instructions for loop: one subtraction, and one conditional jump • Number of iterations required is equal to min{WA , WB} • The total instruction cycles required is roughly 5*(min{WA , WB}) Submission Slide 21 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Software Implementation: Mode L Mapping q Instructions ü Mod operation x 1: • Assume 12 -bits pseudo-random signal, thus 12 -bit mod operation • 96 instruction cycles ü Misc. instructions • Add/if-then-else/table-lookup/load-store variables • 10 instruction cycles ü Totally 106 instruction cycles q Load ü 106/625 us = 0. 1696 MIPS Submission Slide 22 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Software Implementation: Mode H Partition Sequence-SCO (1) q For the first MAU (master-slave pair) ü Distribution unit: Variables initial calculations • Six div/mod operations – 27 bits x 1, 9 bits x 1, 8 bits x 1, 7 bits x 3 – 8*(27+9+8+7*3)= 520 instruction cycles • Two multiplications – 2 bits x 2 – 2*5*2=20 instructions cycles • Misc instructions(logic/compare/jump/add-sub/load) – 30 instruction cycles ü Arrangement unit: • if-then-else/table-lookup – 10 instruction cycles ü Totally 580 instruction cycles Submission Slide 23 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Software Implementation: Mode H Partition Sequence-SCO (2) q For the remaining MAUs within one superframe ü Distribution unit: • Variables update • 25 instructions cycles ü Arrangement unit: • if-then-else/table-lookup • 10 instruction cycles ü Totally 35 instruction cycles q For MAUs after one superframe ü ü Submission The partition sequence is periodic with superframe The maximum length of superframe is 3*79 MAUs Require 237 bits (about 30 bytes) to store one period Table-lookup/index update: 10 instructions Slide 24 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Software Implementation: Mode H Mapping q Instructions ü Mod operation x 1: • Assume 12 -bits pseudo-random signal, thus 12 -bit mod operation • 96 instruction cycles ü Misc instructions • Add/if-then-else/table-lookup/load-store variables • 15 instruction cycles ü Totally 111 instruction cycles ü Load • 111/625 us = 0. 1776 MIPS Submission Slide 25 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Software Implementation: Mode H q The complexity of mode H is the sum of mapping and partition sequence ü Note that partition sequence is not calculated every slot, but every MAU (two slots) ü For the first MAU: • 0. 1776 MIPS + 580/(625 us*2) = 0. 6416 MIPS ü For the remaining MAUs within one superframe • 0. 1776 MIPS + 35/(625 us*2) = 0. 2056 MIPS ü After one superframe • 0. 1776 MIPS + 10/(625 us*2) = 0. 1856 MIPS Submission Slide 26 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Hardware Implementation Assumption(1) q Unit of gate count: NAND gate. q Use one hardware block for multiple occurrences of the same operation. ü Ex: there may be several mod operations, but only one div/mod hardware is needed. q Variable storage/mapping table: 4 gates per bits. q Division/Mod operation ü A=B*Q+R, Q=floor(A/B), R = A mod B ü It can be implemented in hardware by long-division: • Multiple clock implementation, shift-in one bit of operand “A” at each clock. • Require WA clocks to finish one operation. • Gate count required is in proportional to WB. Submission Slide 27 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Hardware Implementation: Mode L Mapping q Hardware blocks: ü Adder • 12 -bits • Gate count = 0. 1 K ü Mod • WB=7 • Gate count = 1 K ü Mapping table • 79*7 bits • Gate count = 2 K q Total gate count = 3. 1 K Submission Slide 28 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Hardware Implementation: Mode H Mapping q Hardware blocks: ü Adder • 12 -bits • Gate count = 0. 1 K ü Mod • WB=7 • Gate count = 1 K ü Mapping table • 79*7 bits • Gate count = 2 K ü Misc • 0. 2 K q Total gate count = 3. 3 K Submission Slide 29 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Hardware Implementation: Mode H Partition Sequence q Hardware blocks: ü Multiplier: 8 bit x 8 bit, parallel multiplier • Gate count = 0. 5 K ü Division/Mod • WB=8 • Gate count = 1 K ü Add/Sub • Gate count = 0. 1 K ü Variable storage and procedure control • Gate count = 1 K ü Misc • Gate count = 0. 2 K q Total gate count = 2. 8 K Submission Slide 30 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Hardware Implementation: Mode H q The complexity of mode H is the sum of mapping and partition sequence ü Direct summation of the two gate count numbers: 3. 3 K + 2. 8 K = 6. 1 K ü Note that the mod/division block can be further shared • Gate count can be reduced to 5. 1 K Submission Slide 31 YC Maa et al. , In. Pro. Comm, Inc.

Integrated Programmable Communications, Inc. November, 2001 doc. : IEEE 802. 15 -01/501 r 0 Complexity Considerations with Reference Numbers for Bluetooth q The hardware implementation of LC is about 70 K-100 K gates q The computation power required for LMP, L 2 CAP, and HCI is about 10 ~ 20 MIPs, while typical processors can easily provide up to 40 MIPs. q The complexity added, in software or hardware, is miniscule! Submission Slide 32 YC Maa et al. , In. Pro. Comm, Inc.