Presentation on theme: "Doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title:"— Presentation transcript:
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [2.4 GHz Narrow Band Frequency Hopping Proposal to TG4g] Date Submitted: [2 May, 2009] Source: [Dr. Soumitri Kolavennu] Company [Honeywell] Address [Add address Street, City, PC, Province/State, Country] Voice:[Add telephone number], FAX: [Add FAX number], E-Mail:[Add e-mail address] Re: [Response to CFP issued January 22nd 2009, document 15-09-077-00-004g] Abstract:[Description of proposed 2.4 GHz Narrow Band Frequency Hopping] Purpose:[For consideration by TG4g for its amendment to IEEE 802.15.4.] 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.
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 2 2.4 GHz Narrow Band Frequency Hopping Proposal to TG4g Providing high capacity, good coexistence, and robustness to interference
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 3 Narrowband FHSS Proposal Advantages Coexists well with WiFi and other users in restricted spectrum Can transmit at over +10 dBm in Europe Can use low-energy edges of WiFi channels Can dodge high-energy narrowband interferers
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 4 Narrowband FHSS Proposal Advantages Offers good mitigation of interference and multipath-induced fades Offers improved receive selectivity over wider-band alternatives Channels can be made even narrower by configuring reduced data rates for control, which also permits increasing the energy per bit while holding output power constant
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 5 Narrowband FHSS Proposal Advantages Built-in end-to-end spatial diversity in communications path –Reduces number of required retransmissions, assisting coexistence Frequency-hopping ARQ protocol addresses missing packets –Each retry is on a different frequency, providing diversity against fading
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 6 2.4 GHz NBFH Proposal Description frequency hopping narrowband system where the channel width is close to 1 MHz thus providing about 80 channels in the 2.4 GHz range. These 80 channels would be partitioned into four groups of 20 channels: –four groups would be partitioned so that they can very easily co- exist with 802.11 systems –802.11 systems usually operate in one of the non-overlapping channels: 1, 6 or 11 20 channel groups would occupy the bandwidth of 802.11 channels –Mode 1 - group that operates in 802.11 channel 1 –Mode 2 - group that operates in 802.11 channel 6 –Mode 3 - group that operates in 802.11 channel 11 –Mode 4 - group defined that operates in the channels between and adjacent to the 802.11 non-overlapping channels
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 7 Coexistence with 802.11 Ensured coexistence with 802.11 channels. NBFH system should be assigned a frequency group that does not interfere with the 802.11 system in the vicinity. –If the 802.11 system is operating in channel 1, for example, the frequency hopping system can be configured to modes 1, 2 or 3. –If all three 802.11 systems are occupied the network can be configured to be in frequency hopping mode where all channels fall either in between or adjacent to the non-overlapping 802.11 channels.
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 8 Capacity of the Narrowband FH system NBFH proposal has 80 channels as compared to 16 channels in 802.15.4. –provides almost 400% more capacity for NBFH systems over DSFH in jurisdictions where such scheduling is permitted.
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 9 Capacity of the Narrowband FH system In the absence of 802.11 channels the capacity of narrowband frequency hopping systems is 2400 devices each reporting once per second as compared to 1600 devices for the 802.15.4 system. Moreover, at this maximum capacity the 802.15.4 system occupies a 100% of the bandwidth in the 2.4GHz frequency band of operation whereas the NBFH system only occupies between 30-40% of the bandwidth
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 10 Robustness to Interference A NBFH system can coexist with a neighboring system very well. This is because at any point of time only about 30% of the bandwidth is being utilized by the system. When two systems are in interference range there will be some collisions between the systems. –However, if the capacity of each system is halved the NBFH system will still exhibit same robustness and reliability.
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 11 Transmit Power and Range European regulations require that a frequency hopping (be it DSFH or NBFH) system operate on 15 or more channels to transmit at higher power levels (20dbm). This is always possible in the NBFH system. Higher transmit power leads to longer range for the transmitted signals. The 15.4 system may have to operate on fewer frequencies because of presence of 802.11 systems and other coordinated or uncoordinated DSFH systems. The 15.4 systems operating at fewer frequencies will have to rely on more number of mesh hops to achieve the same range. This will lead to longer latencies and lower battery life for powered routers.
doc.: IEEE 802.15-< 15-09-0305-00-004g Submission, Slide 12 Summary An alternate physical layer is proposed, based on classical narrow band frequency hopping and other industrial wireless protocols. The proposed system has excellent coexistence with WiFi systems. The narrow band system has very good capacity and excellent coexistence with 802.11 networks. Maximum capacity is achieved through each node picking a frequency from a pseudo random hopping pattern. The NBFH system provides robustness to interference from similar systems operating in the same frequency range. –Two uncoordinated NBFH systems can coexist in the same space. –Combined capacity of the coexisting systems remains the same and the individual system capacities scale down linearly with the number of coexisting systems NBFH systems can have longer range in certain European regions due to higher transmit powers.