Appendix B - Extrapolating Continuous-Flow Information Across Command Levels

APPENDIX

Extrapolating Continuous-Flow Information Across Command Levels

To justify its assumption that demand for communications bandwidth increases by a factor of three between one level of command and the next higher level, the Congressional Budget Office (CBO) used data from a study conducted for the Army's Communications and Electronics Command (CECOM) in 2000 by the Mitre Corporation.⁽¹⁾ Table B-1 displays Mitre's estimates of bandwidth demand at the division, brigade, and battalion command levels; the estimates exclude voice-only communications that are not digital and therefore not relevant to CBO's analysis. The relationships between the commands and the structure of the communications networks associated with those estimates are assumed to exist through 2010 except as noted in Chapter 2. In addition to communications traffic associated with the operations network, the estimates in Table B-1 include bandwidth demand for intelligence data, fire-support data, and network management. Because CBO's analysis deals only with bandwidth demand for the operations net, however, those additional demands must be removed to facilitate comparisons between the two sets of estimates (see Table B-2).

The data in Table B-2 are consistent with CBO's assumption that the demand for communications bandwidth increases by a factor of three from one level of command to the next higher level and decreases by a factor of three at the next lower level. The data also indicate, however, that this assumption is only approximately true--factors somewhat higher or lower than three would also be consistent with the available data. Consequently, CBO has considered the effects on the results presented in Chapters 1 and 2 of using either a factor of two or a factor of four to extrapolate bandwidth demands to command levels above and below that of the division (see Tables B-3 and B-4 for a selection of these variations).

As the tables indicate, for extrapolations that use factors ranging from two to four, significant shortfalls in the supply of bandwidth are projected to occur at the brigade and battalion levels today and at the corps and division levels in 2010. The variations that are not presented (a factor-of-four extrapolation of demand in 2003 and a factor-of-two extrapolation for 2010) do not change those qualitative results.

Table B-1.

Peak Bandwidth Demand at the Digitized Division, Brigade, and Battalion Levels in 2003, by Mission

(In bits per second)

Mission Division TOC Brigade TOC Battalion TOC

Voice Communications 1,424,000 240,000 61,440

Maneuver 1,651,041 315,204 271,394

Fire Support 313,386 311,181 310,134

Intelligence and Electronic Warfare 2,570,327 1,364,168 283,763

Combat Service Support 297,118 128,158 0

Air Defense 30 197 100

Network Management 1,168,335 505,846 54,125

Total 7,424,237 2,864,754 980,956

Source: Congressional Budget Office based on briefing materials developed by the Mitre Corporation for the Army's Communications and Electronics Command, February 29, 2000.

Notes: The bandwidth demand detailed above is for the Amy Common User (communications system) and represents most of the operations net's trunk demand. However, it excludes some older radios and walkie-talkies that, for the most part, support only local, nondigital voice communications that are not relevant to CBO's analysis.

TOC = tactical operations center.

Table B-2.

Peak Bandwidth Demand for the Operations Nets at the Digitized Division, Brigade, and Battalion Levels in 2003, by Source of Demand

(In kilobits per second)

Source of Throughput Demand Division Brigade Battalion

Telephone 1,400 300 100

Army Battle Command System

Classified 300 to 1,000 300 30 to 100

Unclassified 100 to 300 100 0

Unmanned Aerial Vehicles 100 to 300 100 to 300 100 to 300

Video Teleconferencing 1,000 100 to 300 100 to 300

Total 2,900 to 4,000 900 to 1,300 330 to 800

Source: Congressional Budget Office.

Table B-3.

Effective Bandwidth Supply Versus Peak Demand in 2003 Using a Factor-of-Two Extrapolation, by Command Level

(In kilobits per second)

Command Level^a Relative Supply
Versus Peak Demand
(S : D)^b,c

Corps

1 : 1.5 to 3

Division

1 : 5 to 8

Brigade^d

1 : 1.5 to 3

↑

1 : 20 to 30

↓

Battalion

1 : 10 to 20

Company

1 : 4 to 6

Platoon

1 : 2 to 3

Squad/Vehicle

1 : 8 to 14

Source: Congressional Budget Office.

a. At the higher command levels, the table refers to the operations networks only. At lower levels, the distinctions between the various communications networks (for example, operations, intelligence, and fire-support) become less clear.

b. Ranges have been extrapolated from the division level for the corps level and for the company level and below. They have been rounded down to the nearest power of three, which allows the demand per command level to be distinguished while maintaining a conservative (lower) estimate of the aggregate demand.

c. Based on an approximate logarithmic scale, the color coding is as follows: yellow indicates that supply is between about one-third and three times demand (a marginal demand/supply match), and orange signifies that demand is approximately three to 10 times supply. Red(used here for the lower brigade-level relationship and at the battalion level) means that demand exceeds supply by a factor of 10 or more.

d. The up-arrow (↑ ) indicates the throughput rate for communications to equivalent or higher command levels. The down-arrow (↓ ) indicates the throughput rate to lower command levels.


Table B-4.
Effective Bandwidth Supply Versus Peak Demand in 2010 Using a Factor-of-Four Extrapolation, by Command Level

Command Level^a	Relative Supply Versus Demand (S : D)^b

Corps	1 : 12 to 40
Division	1 : 10 to 30
Brigade^c	1 : 2 to 6	↑
	1 : 4 to 10	↓
Battalion	1 : 1 to 4
Company	3 to 4 : 1
Platoon	5 to 8 : 1
Squad/Vehicle	10 to 20 : 1

Source: Congressional Budget Office.
Note: Ranges have been extrapolated from the division level for the corps level and for the company level and below. They have been rounded down to the nearest power of three, which allows the demand per command level to be distinguished while maintaining a conservative (lower) estimate of the aggregate demand.
a. At the higher command levels, the table refers to the operations networks only. At lower levels, the distinctions between the various communications networks (for example, operations, intelligence, and fire-support) become less clear.
b. Based on an approximate logarithmic scale, the color coding is as follows: green (used here for the company, platoon, and squad/vehicle relationships) means that supply is greater than demand by approximately a factor of three or more; yellow indicates that supply is between about one-third and three times demand (a marginal demand/supply match); light orange signifies that demand is approximately three times supply; orange indicates that demand is approximately three to 10 times supply; and red (used here for the corps and division relationships) means that demand exceeds supply by a factor of 10 or more.
c. The up-arrow (↑ ) indicates the throughput rate for communications to equivalent or higher command levels. The down-arrow (↓ ) indicates the throughput rate to lower command levels.

1.	Yosry Barsoum, "Bandwidth Analysis (ACUS Only) of Division Main, Maneuver Brigade TOC, and Tank Battalion" (briefing prepared for the Army's Communications and Electronic Command by the Mitre Corporation, February 29, 2000).