Royal Yacht Squadron Weather and Communications Day

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Royal Yacht SquadronWeather and Communications
Day

• Communications
• Tim Thornton

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Overview

• Receivers NAVTEX, radio, weatherfax etc
• Communications Hardware Choices
• Connecting to the Internet

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NAVTEX

• Network of transmitters with about 250nm range
• Mandatory 518kHz frequency always English
• Optional 490kHz frequency may be in the local
  language

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NAVTEX Transmissions

• Fixed 6 minute time slots every 4 hours for each
  station
• Primarily for navigation warnings every 4 hours
• Secondarily for weather forecasts typically
  every 12 hours
• Urgent info may be sent between regular
  transmission time slots

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NAVTEX

• Transmit every 4 hours
• More navigation information than weather

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NAVTEX Coverage
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NAVTEX Reception Hints

• Ground the antenna cable shield, and use good
  quality cable
• Dont mount by other vertical metal objects
  masts, rigging, stanchions
• Poor reception over land
• Designed for use to seaward of the fairway buoy

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SafetyNet

• Offshore version of NAVTEX
• Transmitted over INMARSAT C (see later)
• Worldwide coverage
• Can be better than NAVTEX reception, e.g. in
  Eastern Mediterranean

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Radio Transmissions

• Numerous voice transmissions
• Local FM radio stations
• Radio 4 on LW
• VHF broadcasts

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Weatherfax

• Weather maps sent over SSB radio
• Northwood and Offenbach transmit in Europe
• Long range reception mid Atlantic
• Takes about 10 mins to receive a map
• A bit fiddly and needs some practice to get the
  best out of it

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Weatherfax
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Weatherfax Software

• Bonito Board Terminal and RadioCom
• Mscan Meteo
• Xaxero Weatherfax 2000
• JVCommThese all generally receive and decode
  Morse, RTTY etc. Bonito will also plot out SYNOP
  weather reports sent over RTTY

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Communications Hardware Choices

• Coverage
• Facilities
• Installation
• Costs

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Coverage Mobile Phone

• Mobile phone GSM and GPRS
• Enhanced with external GSM antenna
• Typically 10 miles offshore
• See www.gsmworld.com for coverage etc.

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Coverage Iridium

• Worldwide
• Except Poland, Hungary, N. Korea
• Antenna must be outside

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Coverage Thuraya

• Satellite coverage Mediterranean, Europe, the
  Gulf, India
• Also includes GSM capability
• Two geostationary satellites

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Coverage GlobalStar

• Land and coastal waters not global
• Also includes GSM capability

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INMARSAT

• 4 geostationary satellites
• Coverage within rectangles
• Blue Mini M,Fleet 33 55 data,Fleet 77 high
  speed

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Facilities
Service Voice Fax Text Data GMDSS Cover
WiFi Via VoIP Via net No 2,000,000 No Marina
GSM Yes Yes Yes 9600 No 10-15 miles
GPRS Via GSM Via GSM Via GSM 30,000 No 10-15 miles
3G Yes Yes Yes gt 380,000 No 10-15 miles
Iridium Yes No Yes 2400 No Global
Thuraya Yes No No 9600 No Med, Middle East
GlobalStar Yes No No 9600 No Offshore
INMARSAT C No Text only Yes 60 Yes Global
INMARSAT Mini-M Yes Yes No 2400 No Offshore
INMARSAT Fleet 33 Yes Yes No 56,000 packet, 9,600 dial-up No Offshore
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In the Pipeline

• Fleet BGAN 492kbps end of this year
• INMARSAT/ACeS linkup smaller, cheaper
  alternative to Iridium rolled out over next 2-3
  years
• Wi-Max longer range WiFi starting being rolled
  out, range 5 32 miles
• GSM HSPA speeds of about 1.8Mbps

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Installation - GSM

• Handheld phone
• Hands free / car kit to hold the phone
• Bluetooth to the PC, ideally
• Or cable or infra-red
• External GSM antenna for best range best up
  high
• Antenna needs good quality cable

• Fixed Phone
• Use DECT cordless phone handset(s)
• Optional connection to fax machine
• Serial cable for data connection to PC
• GSM module can be hidden away
• Data generally faster than handheld phone
• External GSM antenna for best range best up high

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Installation - GSM
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Installation Iridium, Thuraya, Globalstar

• Requires external antenna for reliable satellite
  link simple connection via coax cable
• Serial cable for data connection to PC
• If handset is not designed to be fixed mount,
  ensure enough cable slack for use

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Installation Iridium, Thuraya, Globalstar
Iridium
Thuraya
Globalstar
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Installation INMARSAT

• External antenna required, connected via coax
  cable
• INMARSAT C small and light, 10cm diameter
  approx
• Fleet diameter from 33 to 77 cm. Beware antenna
  weight on larger sizes!
• For packet and dial up services, need separate
  connections to the PC

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Installation - INMARSAT
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Costs (UK inc. VAT)
Service Purchase Monthly sub Voice /min Data per Megabyte
WiFi lt 100 Low Free Free
GSM 200 - 500 0 0.15 - 1.10 2.13 - 8.10
GPRS 0 0 N/A 0.30 - 8.50
Iridium 1800-2500 0 - 25 0.50-1.75 56.80 - 99.50
Thuraya 1400 25.00 0.50 - 1.30 7.10 - 18.50
GlobalStar 800 - 1600 16.60 0.60 - 2.50 8.50 - 30.00
INMARSAT C 1750 - 2700 0 N/A 5783
Mini-M 4250 0 1.60 - 2.80 91 - 160
INMARSAT Fleet 55 16000 0 1.50 - 2.30 10.50 - 14.00 for ISDN, 20 - 26 for packet
INMARSAT Fleet 33 TBA 0 1.50 - 2.30 10.50 - 14.00 for ISDN, 20 - 26 for packet
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E-mail over SSB

• Requires an SSB radio and radio modem equipment
  more expensive than Iridium for example,
  especially with high installation costs of an SSB
• Not a plug and go solution
• Service providers
• SailMail www.sailmail.com
• MarineNet www.marinenet.net

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Connecting to the Internet
Logon authentication
Communications Link
SMTP Server
ISP
POP3 Server
Slower Data rate
DNS Server
POP3 Server
Fast data rate
Internet
Web sites
Communications device
PC
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Using E-Mail Efficiently

• Batch up your e-mails instead of sending
  individually
• Use plain text for outgoing messages
• Send links instead of images
• Dont include original message when replying
• Increase server time-out to allow for slow
  connection and satellite delays
• Disable messaging tools e.g. Windows Messenger,
  ICQ
• Dont use a web browser to read your e-mail

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SmartCom

• Designed for fast operation over slow links
• Sends and receives simultaneously
• If line is dropped, resumes receiving mail where
  it left off instead of starting from scratch
• Minimises the size of outgoing e-mails
• Allows header preview of large e-mails, so you
  can leave them, download or delete
• Optimises TCP/IP settings
• Uses your existing ISP and e-mail addresses
• 39 for GSM only, 69 for satellite and GSM
  communications

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SmartCom
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MailASail

• Server based e-mail service
• Uses your existing ISP
• New e-mail address supplied
• Minimises the size of incoming e-mails by
  converting to plain text and minimising header
  size
• Can also remove any attachments
• Also can remove non-text content from web pages
  for fast browsing but this can cause problems
  with many sites
• Annual or monthly subs - 140/year for each
  service

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Zap

• Requires Outlook, not Outlook Express
• Dial in to their server for e-mail, need a
  separate ISP for web access
• Requires a new zap e-mail address
• Compresses incoming and outgoing e-mails
• Charged by volume of data throughput can be
  expensive
• 70/year 0.35/kilobyte uncompressed

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OnSpeed

• Web and e-mail compression
• Images resized and compressed more on the fly
• Doesnt work with secure sites or some satellite
  phones
• Use own e-mail address and ISP
• Significant speed-up
• Overhead of about 10kbits of data with each
  connection
• 25/year