Presentation on theme: "NCAR & Nextel Presented by Del Harris Bryan Anderson."— Presentation transcript:
NCAR & Nextel Presented by Del Harris Bryan Anderson
Covered Today History of Mobile Communication Cellular at NCAR Current Issues Future Possibilities
History of Mobile Telephone Service 1946 Mobile Telephone Service introduced (MTS) First concept design of cellular in by AT&T 1958 & 1968 AT&T petitioned for frequencies in the 800MHz and up bands IMTS was introduced AT&T built a one dimensional cell system.
History of Mobile Telephone Service (Cont) 1970 FCC requests AT&T to build first cellular mobile vehicle prototype system for allocation bandwidth justification Motorola demonstrated first portable mobile phone handset AT&T is notified by justice department to split apart FCC completes spectrum allocation for cellular 800Mhz A&B bands.
History of Mobile Telephone Service (Cont) 1983 simultaneously AT&T and Motorola build first competing Advanced Mobile Phone Service (AMPS) cellular systems G AT&T relinquishes Bell System’s Wireless Time Division Multiple access TDMA introduced Code Division Multiple access CDMA introduced Nokia introduces first handheld Phone/Computer.
Early Cellular Concept Overview
Cellular at NCAR
NETS: Cellular Transition Early methods –Pager coverage/response issues –Bulky licensed radio’s Cellular’s attractive features –Nation wide mobile phone access –Push to Talk (PTT) –Data features
Adopted Nextel Solution Nextel pluses –Unique PTT feature handy –Good nationwide major Metropolitan coverage Nextel shortfalls –Internal building coverage –Nationwide coverage inconsistent –Rural coverage –Lack of roaming
Nextel ML Building Coverage Solution Approached Nextel directly. –Nextel did ML Site evaluation. –Nextel Solution costly. –Acquired Nextel Design Implementation Evaluated Nextel Solution –Acquired few basic system components. –Evaluated components –Acquire & Install Phase 1 products –Acquire & Install Phase 2 products –Expand coverage areas
New Nextel SMR800 System Systems Specifications –SMR800 Single Band limited Repeaters Antenna –Open Band components limits Combiner/dividers.8-2.3GHz Directional Couplers.8-2.3GHz Lightning Protector.7-2.7GHz Cabling GHz
Nextel Network Testing Spectrum Analyzer iDEN internal handset diagnostic mode. – Diagnostic Access code i836 Keys: Press #Key,*Key, Menu Key, and Right Arrow Key sequence in less than 5 seconds. Phone will enter “Trace Mode” Menu Two Operational Diagnostic modes
ML System Diagram ML Nextel SMR800.dwg
Additional Nextel Building Site Installations Design: Pseudo Complete –ML –FL4 –FL3 Design: Inherited Partial Installs –CG1 –FL2
ML Nextel Building System Issues Ongoing –Building to system call handoffs –Difficult Coverage Small nodes Exterior areas New –Nextel Frequency Re-band Building Network wide upgrade needed –Nextel/Sprint Merger
Sprint/Nextel Merger Sprint acquired Nextel –Two different Technologies –Two different Bands Nextel’s future? –Frequency band
Upgrade Present System Pro’s –Existing Nextel users not displaced –SMR 900 dead air & drop calls will be eliminated. Con’s –Complete System replacement, minus media, costly. –Live with present system pitfalls –Nextel uncertain future
Correct Nextel Issues & Install Second Vendor Solution Pro’s –Dual system redundancy/options –Existing Nextel users not displaced –Overcome Nextel Nationwide short falls Con’s –Complete Nextel System overhaul minus media replacement costly –Complete Second System Installation required. –Possibility of Dual System Interference –Nextel uncertain future
Abandon Nextel & After Installation of a New Vendor Solution Pro’s –Overcome Nextel Nationwide short falls –No further investment in present systems. Con’s –All UCAR users will need to buy in. –New system technology and installation costs an unknown at this time.
New FCC Public Safety Building Coverage Issues Public Safety –First Responder Communications 200 Cities have already adopted. Present SMR800 system partially accommodates Public Safety. –Future may include 700MHz.
FCC & Cellular Vendor Concerns over in Building Repeaters FCC –Interference Vendor –Interference –Experienced personnel –Maintained
American Signal Multiplexing Methods TDMA is TDM based GSM is TDM based iDEN Nextel is TDM based CDMA by Qualcomm Technologies
TDMA Disadvantages TDMA Utilizes a small piece of total frequency spectrum based on specific cell location TDMA all transactions require specific amount of allocated time slots. TDMA rigid timing rotation to multiplex several calls.
Balanced CDMA system advantages over TDM systems CDMA only uses as much TX time as a conversation requires. CDMA utilizes larger frequency spectrum to spread out signal pieces instead of just the one for TDMA. CDMA spectrum efficiency allows for 2-3 times more voice capacity then TDMA. CDMA has Enhanced privacy. CDMA access to all parts of spectrum
CDMA Don’t be fooled –CDMA Probably the Future Protocol Still limited to vendors investments –Nation Wide coverage –CDMA protocol Upgrades
Wireless Voice: The Skies the limit Conclusion: –Knowns We need to define what are OUR requirements are! –Voice »In Building! »Nation Wide! »Rural! »PTT? –Data?
Wireless Voice: The Skies the limit (Cont) Conclusions: –Unknowns Selected systems technology Selected systems band Selected system longevity Selected systems shortfalls