1 / 12

Deployment Challenges of Wi-Fi Telephony

Deployment Challenges of Wi-Fi Telephony. John DiGiovanni Director of Marketing Staff Technologist john.digiovanni@xirrus.com. Voice over Wi-Fi – It’s Coming!. 802.11 Standards Review. 802.11b Ratified 1999 – Up to 11Mbps in the 2.4GHz Band 802.11a

alden-gallagher
Download Presentation

Deployment Challenges of Wi-Fi Telephony

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Deployment Challenges of Wi-Fi Telephony John DiGiovanni Director of Marketing Staff Technologist john.digiovanni@xirrus.com

  2. Voice over Wi-Fi – It’s Coming!

  3. 802.11 Standards Review • 802.11b • Ratified 1999 – Up to 11Mbps in the 2.4GHz Band • 802.11a • Ratified 1999 – Up to 54Mbps in the 5GHz Band • Not backward compatible to 802.11b • 802.11g – Backward Compatible to 802.11b • Ratified 2001 – Up to 54Mbps in the 2.4GHz Band • Backward compatible to 802.11b • 802.11n – Ratified Standard Expected 2008

  4. Voice over Wi-Fi Challenges • Shared Medium, Collision Avoidance & Limited Bandwidth • Channel Allocation, Planning & Usage • Quality of Service • 802.11e available for voice • Mapping QoS priorities through the wired network • Wi-Fi Architecture Choices

  5. Ch# 1 2 3 4 5 6 7 8 9 10 11 2.4GHz ISM Band Ch# 1 6 11 Channels & Capacity – 802.11b/g Only 3 Channels are Non-overlapping 33Mbps in 802.11b of Total Capacity 162Mbps in 802.11g of Total Capacity Voice Calls Proportional to Channel Usage

  6. Ch# 36 40 44 48 52 56 60 64 149 153 157 161 Ch# 100 104 108 116 120 112 124 128 132 136 140 Channels & Capacity – 802.11a • 12 channels for 802.11a • Use as many Channels as possible • Reuse them as often as possible 5GHz UNI Band FCC has approved 11 more channels Up to 1.24Gbps of Total Capacity

  7. Quality of Service • 802.11e (Over the Air) • Packet prioritization for downstream traffic • Wired Class of Service is mapped to wireless TCID settings

  8. Architecture Choices 1st Generation: Independent APs • 108Mbps per Cell (2 channels) • Individually Managed 2nd Generation: Controller + APs • 108Mbps per Cell (2 channels) • Centrally Managed 3rd Generation: Controller + Ultra Thin APs • 108Mbps per Area (2 channels) • Good for Roaming

  9. Architecture Choices Wi-Fi Array • Up to 864Mbps of Bandwidth per cell • Up to 16 channels per cell • Sector Antenna System • Long Range • Very high client capacity • Very high voice capacity

  10. Take Aways • Design for Performance – Not Just Coverage • Over provision for wireless (same as for wired) • Use all available 802.11a/b/g channels simultaneously • Reuse channels as often as possible • Designed for Voice • More users at higher data rates = less contention/latency • Insist on standards-based QoS (802.11e / scheduled access) • Map QoS through the wired network

  11. Thank You John DiGiovanni Director of Marketing Staff Technologist john.digiovanni@xirrus.com

More Related