Enterprise Solutions from Continental Wireless

 Existing Enterprise Communications network overview.

Figure One shows the existing network for a hypothetical enterprise. This system grew over a period of time, and bases connectivity between locations on leased T1 facilities. Headquarters contains the main PABX telephone system as well as both the gateway to the Internet and to the Public Switch Telephone Network (PSTN) for all other locations. Each branch office is served by a single T1. The T1 carries telephone trunks configured as fractional T1 circuits, with the remainder of the available bandwidth available for both Intranet and Internet data Traffic.

The factory location is served in a similar fashion, multiple T1's are provided to provide for automated manufacturing and accounting processes as well as additional voice services.

A total of 10 T1's are used to support these facilities at an annual cost in excess of 90,000 dollars in lease payments to the local services provider for a total of 15 Mbps of capacity between all locations.

Management would like to reduce recurring costs associated with these T1's, while adding additional capacity for implementation of new data and security services.

Fig One - Existing Overview

Table One - Existing Transmission System

Location

Distance

Bearing (from HQ)

Current Traffic

Notes

Branch A

2.6 Miles

NNW

2 Voice + Data (1 T1)

• Branch office voice traffic configured as fractional T1 circuits landing as Branch PABX trunks, remainder of T1 capacity carries Intranet and Internet data services

• One T1 from factory crossed to one T1 to warehouse for logistics support system

• Average cost of each T1 is 750 dollars per month, or 90,000 dollars per year for all span lines.

Branch B

4.7 Miles

NW

2 Voice + Data (1 T1)

Branch C

3.8

NWW

4 Voice + Data (1 T1)

Branch D

3.25

SSE

2 Voice + Data (1 T1)

Branch E

4.2

SE

4 Voice + Data (1 T1)

Factory

6.0 Miles

NE

12 Voice + Data (3 T1)

Warehouse

4.2 Miles

E

6 Voice + Data (2 T1)

Proposed Wireless Solution for Transmission Subsystem

Wireless Design Considerations

A hybrid wireless system using both Point-to-Point and Point-to-Multipoint Microwave subsystems, using the U-NIII bands to minimize interference with other wireless systems is selected as the wireless infrastructure.

• Point Multipoint was chosen to serve the branch offices as maximum capacity at minimum cost. The 5.7 U-NIII band 3 was chosen for the PMP subsystems to make use of the higher EIRP allowed under Part 15 for greater range.

• Point to Point (backhaul) configurations were selected for the Factory and Warehouse Locations for the greater capacity available. 5.2 GHz U-NIII band 2 was chosen for the point to point links to minimize interference with the PMP subsystems.

Budgetary estimate for the wireless transmission system to replace the currently leased T1 facilities is under 60,000 dollars, installed. Less than a 9 month payback.

Fig Two - Proposed Wireless Infrastructure

Table Two - Proposed Wireless Link Characteristics

Path Designator

Type

Sector

Bearing

Capacity

Throughput

Path Length

Frequency

Notes

HQ - Branch A

PMP

NW

6 Mbps

2.6

5.7 GHz

• PMP Channel 1 operating frequencies used for both active sectors to conserve Spectrum. PMP Channels 2 & 3 reserved for future expansion of the PMP Access Point.

• Effective PMP capacity is enhanced  by  idle channel detection as well as compression in the IP/TDM converters. Capacity is also effectively increased by statistical multiplexing offered in PMP operation with native IP overhead formatting.

HQ - Branch B

PMP

4.7

HQ - Branch C

PMP

3.8

HQ - Branch D

PMP

SW

6 Mbps

3.25

HQ - Branch E

PMP

4.2

HQ - Factory

P2P

NE

20 Mbps

6

5.2 GHz

HQ - Warehouse

P2P

W

20 Mbps

4.2

Simplified Block Diagram

• Global Positioning Satellite (GPS) subsystem provides system timing.

• Network Management and monitoring capability provided by Network Manager Console (NMC) installed at Headquarters building. Note that a laptop (not shown) is provided for trouble shooting and network management from remote locations.

• Branch Offices - Microwave links have nominal 6 Mbps throughput.
  One of five branch offices shown. PABX traffic, previously served by T1 span lines, now provided over the IP stream utilizing TDM/IP conversion equipment.

• Factory/Warehouse - Microwave links have nominal 20 Mbps throughput. One of two Point to Point locations shown. PABX traffic carried by TDM/IP subsystem. Back to Back T1 data traffic now carried by native TCP/IP streams.

• Idle channel detection, and voice compression technology releases Voice capacity for data services use automatically.

Fig Three - Simplified System Block Diagram