Hand Held Products Introduction to 2.4GHz Wireless Solutions

1. Hand Held Products Introduction to 2.4GHz Wireless Solutions

2. Table of Contents RF Network Components Intro to 2.4GHz RF LAN configuration Access Points Wireless Hopping AP Configuration

3. Wireless Network Nomenclature Destination computer which houses RF application/database Host Network media used to connect RF network components Backbone RF network component which establishes communication between host and terminal Controller Radio Frequency spectrum used to communicate wirelessly RF technology Component attached to the backbone that sends and receives RF transmissions Base Station/ Access Point RF enabled hand held computer capable of standalone processing RF HHC RF Terminals RF enabled terminal not capable of standalone processing

4. RF Network Components Network or Direct Connected

5. Emulation Communication(Universal Gateway) Network or Direct Connected

6. Client/Server Communication(Telnet Client) Network or Direct Connected X

7. Wireless LAN Technologies Infrared Light Narrowband SpreadSpectrum 3 cm 0.03 cm 30 cm 3 m 0.3 cm 3x105A 3,000 m 300 m 3x106m 3x105m 30 m 30,000 m WAVELENGTH Very Low Frequency VLF LF MF HF VHF UHF SHF EHF INFRARED BAND DESIGNATIONS ACTIVITIES Microwaves FREQUENCY 10 GHz 1 THz 1 GHz 100 MHz 100 GHz 1013Hz 100 kHz 1 MHz 100 Hz 1 kHz 10 MHz 10 kHz FM Broadcast 2.4 GHz (ISM) AM Broadcast 902 MHz (ISM) Audible Range 5.8 GHz (ISM) • Typically Line-of-site • Short Range Connectivity • In Room Application • High Data Rate Potential • Specific Frequencies • Individual User License • Low Data Rates • Interference Resistance • Secure • License Free Use

8. Spread Spectrum Technology Secure • Military applications • Difficult to detect or decode Interference resistance • Direct sequence signals are spread • Frequency hopping signals move No end user license required from the FCC!

9. Frequency Hopping Example Frequency Hopping Patterns (4 Channels , 10 frequencies) Channel 1 2 3 4 2 4 6 8 10 1 3 5 7 9 8 5 2 10 7 4 1 9 6 3 4 8 1 5 9 2 6 10 3 7 3 6 9 1 4 7 10 2 5 8 1 2 3 4 5 6 7 8 9 10 The spectrum at one slice (hop period) in time

10. 802.11 Interoperability Gap The specification is now complete Testing for conformance or interoperability is now being completed Many different options exist FH or DS? How to Roam?

11. Introducing the WLI ForumAnd the OpenAir™ Specification Deliver multi-vendor wireless LANs in 1998 and beyond Multiple devices on a single wireless backbone Scanners Pen computers Notebook computers Super rugged computers Peripheral Connectivity No company makes all the necessary products

12. AMP BASS Citadel Comtron Cruise Technologies Fujitsu Hand Held Products Hewlett-Packard IBM Intermec Kansai Kinetic Computer LXE Matsushita Mitsubishi Monarch Marking Systems Newton NTT-IT Percon Proxim Seiko Epson Telos WLIF Membership Winter 1997-98

13. 2.4 GHz Radio Modulation FSK - Frequency Shift Keying QFSK / BFSK QFSK - normal (1.6 Mbps) BFSK - fallback (800 Kbps) Harsh radio environments

14. “0” “1” ¦- 500 KHz ¦+ 500 KHz BFSK (Binary Frequency Shift Keying) Example ¦

15. “10” “11” “00” “01” ¦- 300KHz ¦- 100KHz ¦+ 100KHz ¦+ 300KHz QFSK (Quaternian Frequency Shift Keying) Example ¦

16. Carrier Sense Multiple Access Collision Avoidance Listen RTS CTS Sender Receiver Data Ack CSMA/CA with RTS/CTS

17. Configuration Terminology TermTerm Definition Master Coordinates station hopping Station Must be synchronized to a Master Alternate Master Becomes a Master if no other Masters are found Channel Hopping sequence Domain Wireless subnet, used for roaming Security ID Must match on both Master and Station to synchronize

18. Station Types Master Determines the Channel (hopping sequence) and Subchannel Keeps the radios in synchronization Repeats the network messages to hidden nodes Any radio can be designated as Master (Access Point, PC Card or ISA)

19. Station Types Station Follows the instructions of the acting Master Receives Channel & Subchannel assignment from Master

20. Station Types Alternate Master Takes over Master functions when Master is not present, otherwise behaves as a Station Set in a peer-to-peer network , NEVER in a roaming network Typically only 1 Alternate Master defined • Radio overhead added to network • Master Resolution Protocol

21. Channel The frequency hopping pattern Choice of fifteen (1-15) Only set on Active Master (Master, Alternate Master) Each Channel provides 1.6 Mbps Channel Frequency Hop 1 2 9 2 4 6 8 10 1 3 5 7 9 2 4 6 8 10 1 3 5 7 9 2 Same Channel but hops are skewed in time

22. S/C 1 S/C 1 C 1 C 1 Radio Frame Radio Frame Master Station Frequency / Subchannel Channel 11 12 21 41 61 81 101 11 31 51 71 91 92 22 42 62 82 102 12 32 52 72 Subchannel A software code which creates additional logical subdivision of Channel Does not affect radio Channel Choice of fifteen Subchannels (1-15) Only set on Active Master (Master, Alternate Master)

23. Basic Service Area (BSA) Sometimes called a “cell” or “workgroup” A group of RangeLAN2 units that communicate through wireless media only (no wired backbone) Always has one Active Master All station types share one Channel / Subchannel unique to that BSA

24. Domain A software code Used to establish an Extended Service Area (ESA) Choice of sixteen (0-15) Set on ALL Station Types

25. Security ID 20 alpha-numeric character parameter 1,048,576 possible choices Set on ALL Station Types Scrambled, set and stored in EEPROM (Hardware) Impossible to discover ID or recover ID if forgotten RangeLAN2 radios will NOT hear each other unless they are on the same domain AND security ID

26. Extended Service Area (ESA) Two or more BSAs that share a common wired network segment BSAs overlap in coverage Stations may roam seamlessly between BSAs but must stay within ESA coverage

27. Roaming Always set up Access Points as Masters All Access Points must be on the same Domain and Security ID All Access Points must have a unique Channel/Subchannel pair Workstations must be set as stations with the same Domain and Security ID Workstations roam when they lose sync with the Access Point Roaming will only occur through Access Points (not to an ISA card in a file server)

28. Router No Roaming Across Routers Network address restriction

29. Roaming and Subnets Roaming between subnets not currently possible using standard IP stacks Roaming between APs in the same subnet is possible Problem: When a client roams from one subnet to another, the default gateway for that subnet is different.

30. Roaming Outside Coverage Area? Results are NOS dependent

31. Roaming in an ESA D ____ C ____ S ____ S/ID ____ D ____ C ____ S ____ S/ID ____ D ____ C ____ S ____ S/ID ____

32. Radio Specifications 100 or 500 mW output 1.6 Mbps radio data rate Up to 100' indoor range Up to 1000’ in open spaces 2.40 - 2.4835 GHz frequency range (U.S.) Spread Spectrum frequency hopping 15 independent channels

33. AP Features Small form factor Filters at 14,800 packets/sec Automatic throughput optimization Remote configuration via modem User authorization table Mounting options Antenna options Easy-to-use menu trees

34. Access Point 3 Front LEDs State Unit off Power-On Diagnostics Diagnostics Failed Normal Status LED Off Orange Red Green Radio LED Off Off Off Blinking Yellow Back bone LED Off Off Off Blinking Green

35. Access Point 10Base-T Link Indicator Master LED Synched to Master LED 3 Back panel LED’s

36. Extension Points Provides wireless LAN Access Point functionality for areas hard to reach with network wiring

37. How EPs Work Two simultaneous functions Provide Basic Service Area (BSA) to mobile stations Rebroadcast mobile station traffic to wired network Two radios (10BaseFreeTM architecture) BSA radio - supports local mobile stations • Backbone (BB) radio - rebroadcasts traffic from • BSA to AP on the wired network

38. Extension Point Architecture Backbone Radio (BB) Basic Service Area Radio (BSA) • Always configured as a Station Connects to an “upstream” AP Directional antennas Always configured as a Master • Connects to roaming clients • Use omni antennas or directional antennas

39. Single Wireless Hop

40. Multiple Hop Scenario • Maximum three hops, as shown

41. Tree Topology • Maximum three wide, as shown

42. Fault Tolerant Configuration • Solid links represent preferred links • Slotted links represent fallback links

43. Access / Extension Point Antennas Omnidirectional Standard office antenna Higher Gain Omnidirectional Greater range Patch 180° Directional Yagi Highly directional

44. MAC Optimize Helps improve throughput for smaller networks In most cases, use Auto 1 node synchronized to a Master is Very Light Between 2 and 8 concurrent nodes synchronized to same Master is Light (=0) > 8 concurrent nodes is Normal (=1) Set on a Master or Alternate Master

45. Roaming Configuration Determines how quickly Stations roam Heavy overlapping Access Point coverage is Fast (=2) Maintains high throughput for each node Decreases size of cell Normal Access Point coverage is Normal (=1) Throughput will not change Sparse Access Point coverage is Slow (=0) Wireless nodes will not roam until nearly out of range Increases size of cell Set on Stations and Alternate Masters

46. AP Configuration Currently 3 methods for AP configuration Serial Connection (null modem cable) Telnet (requires IP address) Web Browser (requires IP address)

47. Questions ????