U.S. patent application number 11/323656 was filed with the patent office on 2006-06-29 for apparatus and method for providing dynamic communications network traffic control.
This patent application is currently assigned to BellSouth Intellectual Property Corporation. Invention is credited to James R. Bacon, William R. Matz, Vernon Meadows, Douglas R. O'Neil.
Application Number | 20060142018 11/323656 |
Document ID | / |
Family ID | 32041811 |
Filed Date | 2006-06-29 |
United States Patent
Application |
20060142018 |
Kind Code |
A1 |
Matz; William R. ; et
al. |
June 29, 2006 |
Apparatus and method for providing dynamic communications network
traffic control
Abstract
Systems and methods for controlling traffic on a communications
network include dynamic and flexible control plans that enable
service providers to control or influence customer access to
communications facilities. Communications facilities are monitored
to identify network elements, such as cell sites, that are
overloaded. When the traffic intensity on a particular facility
exceeds a predetermined level, either active or passive control is
imposed on subscribers that are in the geographic area of the
facility. Active control involves blocking, delaying or disrupting
subscriber calls during the critical time period. Passive control
involves providing cost incentives or disincentives during low or
peak periods of traffic intensity. Customers are notified of the
commencement and/or termination of active or passive control
preferably via SMS. When implemented with stationary cellular
service, the systems and methods aid in traffic engineering and
provide opportunities for customers to reduce the cost and increase
the accessibility of telephone service.
Inventors: |
Matz; William R.; (Atlanta,
GA) ; O'Neil; Douglas R.; (Marietta, GA) ;
Bacon; James R.; (Norcross, GA) ; Meadows;
Vernon; (Lilburn, GA) |
Correspondence
Address: |
MERCHANT & GOULD LLC;Attn: Murrell W. Blackburn
P.O. Box 2903
Minneapolis
MN
55402-0903
US
|
Assignee: |
BellSouth Intellectual Property
Corporation
Wilmington
DE
|
Family ID: |
32041811 |
Appl. No.: |
11/323656 |
Filed: |
December 30, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10261132 |
Sep 27, 2002 |
7006831 |
|
|
11323656 |
Dec 30, 2005 |
|
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|
Current U.S.
Class: |
455/452.2 |
Current CPC
Class: |
H04W 4/24 20130101; H04M
2215/2026 20130101; H04M 2215/0152 20130101; H04W 24/08 20130101;
H04M 2215/0184 20130101; H04M 15/00 20130101; H04M 15/80 20130101;
H04M 15/8083 20130101; H04M 2215/0112 20130101; H04W 48/06
20130101; H04M 15/8016 20130101; H04M 15/81 20130101; H04W 28/08
20130101; H04M 2215/7414 20130101; H04M 2215/32 20130101 |
Class at
Publication: |
455/452.2 |
International
Class: |
H04Q 7/20 20060101
H04Q007/20 |
Claims
1. A computer program product comprising a computer-readable medium
having control logic stored therein for causing a computer to
control communications traffic based on a traffic control plan
associated with a communications network, the control logic
comprising computer-readable program code for causing the computer
to: when traffic conditions at a network element are congested,
verify which affected communications devices still have permission
to access the communications network when the traffic conditions
are congested; and implement a traffic control measure according to
a control plan associated with one or more of the affected
communications device; wherein the traffic control measure includes
causing the computer to permit access to the communications network
for some of the affected communications devices based on a grade of
service associated with the one or more affected communications
devices.
2. The computer program product of claim 1, wherein the traffic
control measure further includes causing the computer to alter a
cost of communicating for the affected communications devices that
based on the control plan still have access to the communications
network when the traffic conditions are congested.
3. The computer program product of claim 2, wherein causing the
computer to alter a cost of communicating comprises causing the
computer to increase a price of communicating for the affected
communications devices that based on the grade of service still
have access to the communications network when the traffic
conditions are congested.
4. The computer program product of claim 3, wherein causing the
computer to increase a price of communicating comprises causing the
computer to increase a price for communicating during congested
traffic conditions on a per minute basis based on the grade of
service.
5. The computer program product of claim 3, wherein causing the
computer to increase a price of communicating comprises causing the
computer to charge a monthly service fee or activation fee for the
affected communications devices that based on the grade of service
still have access to the communications network when the traffic
conditions are congested.
6. The computer program product of claim 3, wherein the affected
communications devices comprises wireless devices communicating
over a wireless network and wherein the computer comprises one of
an application server, a radio port controller, or an access
control device.
7. The computer program product of claim 6, wherein the wireless
devices and wireless network operate via one of code division
multiple access (CDMA) or global system for mobile communications
(GSM).
8. A traffic control system for controlling traffic on a
communications network, the system comprising: a network control
center that receives traffic data identifying traffic conditions
associated with at least one element of the communications network;
and a traffic control application that, for one or more of the
network elements: receives information identifying what grade of
service is associated with one or more communications devices that
still have permission to access the communications network when the
traffic conditions are congested; and when traffic conditions are
congested, implements communications via the communications network
for the communications devices associated with a subscriber
identifier having the grade of service denoting continued access to
the communications network during congested traffic conditions.
9. The system of claim 8, wherein the traffic control application
is further operative to alter a cost of communicating for the
communications devices that based on the grade of service still
have access to the communications network when the traffic
conditions are congested.
10. The system of claim 9, wherein the traffic control application
operative to alter a cost of communicating is operative to increase
a price of communicating for the communications devices that based
on the grade of service still have access to the communications
network when the traffic conditions are congested.
11. The system of claim 10, wherein the traffic control application
operative to increase a price of communicating is operative to
increase a price for communicating during congested traffic
conditions on a per minute basis based on the grade of service.
12. The system of claim 10, wherein the traffic control application
operative to increase a price of communicating is operative to
charge a monthly service fee or activation fee for the
communications devices that based on the grade of service still
have access to the communications network when the traffic
conditions are congested.
13. The system of claim 8, wherein the communications devices are
wireless devices communicating over a wireless network.
14. The system of claim 13, wherein the wireless devices and
wireless network operate via one of code division multiple access
(CDMA) or global system for mobile communications (GSM).
15. A method for controlling communications traffic based on a
traffic control plan associated with a communications network, the
method comprising: receiving information identifying what grade of
service is associated with one or more communications devices that
still have permission to access the communications network when
traffic conditions are congested; and when traffic conditions are
congested, permitting communications via the communications network
for communications devices associated with the grade of service
denoting continued access to the communications network during
congested traffic conditions.
16. The method of claim 15, further comprising altering a cost of
communicating for the communications devices that based on the
grade of service still have access to the communications network
when the traffic conditions are congested.
17. The method of claim 16, wherein altering a cost of
communicating comprises increasing a price of communicating for the
communications devices that based on the grade of service still
have access to the communications network when the traffic
conditions are congested.
18. The method of claim 17, wherein increasing a price of
communicating comprises increasing a price for communicating during
congested traffic conditions on a per minute basis based on the
grade of service.
19. The method of claim 17, wherein increasing a price of
communicating is operative to charge a monthly service fee or
activation fee for the communications devices that based on the
grade of service still have access to the communications network
when the traffic conditions are congested.
20. The method of claim 15, wherein permitting communications for
the communications devices comprises completing communications for
wireless devices communicating over a wireless network and wherein
the wireless devices and wireless network operate via one of code
division multiple access (CDMA) or global system for mobile
communications (GSM).
Description
RELATED APPLICATION
[0001] This patent application is a continuation of U.S. patent
application Ser. No. 10/261,132, entitled "Apparatus and Method for
Providing Dynamic Communications Network Traffic Control," filed on
Sep. 27, 2002 and assigned to the same assignee as this
application. The aforementioned patent application is expressly
incorporated herein, in its entirety, by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to telecommunications, and
more particularly, to systems and methods for providing reduced
cost cellular service by minimizing the cost of equipment,
activation and service.
BACKGROUND OF THE INVENTION
[0003] "Plain old telephone service" (POTS) is ubiquitous in much
of the world today. For a variety of reasons, however, cellular
technology sometimes provides an attractive alternative to POTS,
even for customers that do not need the mobility that cellular
service inherently provides. For example, a low-income customer
such as a college student may be somewhat transient, making
repeated initiation and termination of POTS costly and
inconvenient. The college student may share an apartment, rent a
portion of someone else's home, or otherwise live in a situation in
which expensive and intrusive rewiring of an additional POTS line
would be unwelcome.
[0004] Provision of POTS requires the service provider to invest in
infrastructure, such as placement and maintenance of buried and
aerial telephone wire and cable, and of associated facilities. A
significant portion of the populace may not have access to such an
infrastructure. Even where the infrastructure exists, poor
maintenance, and rugged conditions can impact the level of
services. Thus, in some rural regions or developing countries, POTS
is either unavailable or unreliable, with frequent outages and poor
quality, even as compared to cellular service.
[0005] In these and other instances, cellular service would be
preferable to POTS. Cellular service can be provided without
installing and maintaining physical interconnections between the
provider and the customer. The upfront and ongoing cost
differentials between cellular service and POTS, however, present
an entry barrier for many customers. The cost differentials are
primarily attributable to the relatively expensive components in
most cellular telephones, to labor and equipment required to
activate the cellular telephone, and to monthly service charges for
cellular service.
[0006] A typical cellular telephone includes a rechargeable
battery, battery charging components, a display screen, an antenna,
and electronic elements for providing continuous service while
"handing-off" from one cell site to another. A basic non-cellular
"land-line" telephone requires none of these elements to provide
access to POTS, and thus is less expensive to manufacture. In fact,
a cellular telephone can retail for several times the price of a
basic land-line telephone.
[0007] The cost of cellular service is typically exacerbated by the
"overhead" expenses incurred by the cellular service provider
(CSP). Although cellular service is provided by a CSP, the customer
typically purchases the cellular telephone from a retailer, such as
an office supply or electronics store. Each cellular telephone must
then be activated prior to first use.
[0008] In a typical approach, at the point of sale, the retailer
collects the customer information that is required for activation.
The information collected may include name, address, home telephone
number, office telephone number, social security or other
identification number, and payment information. The retailer then
sends this information to a customer activation center (CAC). The
CAC performs a credit check, assigns a cellular telephone number,
and relays the cellular telephone number back to the retailer. The
retailer then programs the cellular telephone number into the
cellular telephone.
[0009] Either or both the retailer and the CAC receive a fee for
performing or arranging for a cellular telephone number or
programming the cellular telephone number into the cellular
telephone. Thus, the need for an intermediate business or
organization to obtain a cellular telephone number or to program
the cellular telephone increases the cost to the customer or
decreases the revenue to the CSP.
[0010] In another approach, the customer may order the cellular
telephone through the mail or may purchase it directly from a
retailer that does not perform the activation sequence. When the
cellular telephone arrives, the customer must arrange to obtain a
cellular telephone number for the cellular telephone and to program
the cellular telephone number into the cellular telephone. To do
so, the customer may directly call the CAC, either using the
cellular telephone or another telephone. If the customer calls
using the cellular telephone, the cellular telephone has a dummy
Mobile Identification Number (MIN) which permits access to the
cellular telephone network. This feature eliminates the need for
the services of an intermediate business or organization because
the customer communicates directly with the CAC. The CAC performs
the credit check and assigns the cellular telephone number to the
cellular telephone. The customer then manually programs the
cellular telephone number into the cellular telephone, either by
using the instruction manual or by listening to instructions from
the CAC. In some instances, the cellular telephone is programmed to
allow the CAC to remotely program the cellular telephone number
into the cellular telephone. The need for the retailer or a service
provider to program the cellular telephone is thereby
eliminated.
[0011] Some customers encounter difficulty in performing the
programming because of unfamiliarity with the concept of
programming, or because of inadequate instructions in or loss of
the instruction manual. In addition, for the CAC to assist the
customer in programming the cellular telephone, the customer must
be able to tell the CAC the make and, in some instances, the model
of the cellular telephone. The make may be obvious if the cellular
telephone is sold under the label of the manufacturer, but may not
be obvious if the cellular telephone was sold under a private
label. The model number, and any revision number, may not be listed
or may be difficult to determine without opening the case of the
cellular telephone, which may void the warranty. Consequently, a
customer may find the self-programming approach somewhat
frustrating.
[0012] In addition to up-front costs, cellular service may also be
impracticable for some customers due to monthly service fees.
Cellular service providers must also be responsive to the market
demand for lower cellular rates. This demand is evidenced by
frequent new and/or special rate plans advertised by various
cellular service providers who must compete for customers as the
market becomes saturated with cellular users.
[0013] Cellular customers typically pay a flat fee for service, and
an additional fee based on the number of airtime minutes that the
customer has used. Other cellular service plans may require the
customer to purchase a bulk quantity of airtime minutes, for which
the customer must pay even if the airtime is not actually used.
Customers who choose to pay "by the minute" typically receive rates
that are less favorable than rates available to those who purchase
airtime in bulk. Furthermore, customers who choose to purchase
airtime in bulk further reduce per minute rates by purchasing
increasingly larger blocks of minutes. However, these bulk
purchasers effectively ensure that their cellular telephone bills
will never be lower than the minimum quantity of minutes
purchased.
[0014] Airtime rates also typically vary based upon the time of day
and day of the week. CSPs impose different rates at different times
as part of the process of "traffic engineering." Traffic
engineering involves calculating and controlling the amount and
location of communications equipment required to handle
communications traffic, including telephone, voice, data, images,
and video. Rather than simply installing expensive communications
equipment to keep pace with traffic, many CSPs attempt to control
expenditures by controlling the traffic. To encourage "peak
shifting," CSPs raise the per minute rates for cellular service
during peak periods. For instance, weekend rates are lower than
weekday rates, and nighttime rates are lower than daytime rates.
These rate variations enable the CSPs to increase the efficiency of
capital expenditures on infrastructure, such as cell site
installations.
[0015] Each CSP must statistically determine the times and days
that typically experience peak usage, and encourage customers to
avoid using cellular service during those periods. Once peak and
off-peak intervals are statistically established, the CSP creates
rate schedules accordingly, which are then published to the
customers of the CSP. The rate schedules typically impose the
highest rates during statistically peak periods, which are usually
weekday mornings and afternoons. Somewhat lower rates typically
apply to statistically more moderate periods, such as weekday
evenings. The lowest rates typically apply to statistically
non-peak periods, such as weeknights and weekends. Actual usage
patterns vary, however, according to any number of parameters, such
as the season, local activities (such as major sporting events),
holidays, highway traffic conditions, school terms, or the weather.
Thus, a disadvantage of such statistics-based rate-making systems
is that a CSP's rate schedule may discourage customer usage during
a "peak" period that is actually experiencing low call traffic, and
may encourage customer usage during an "off-peak" period that is
actually experiencing high call traffic. The variability in the
correlation between statistical prediction and actual call traffic
can result in lost revenues and network overloads. Statistics-based
rate schedules are also disadvantageous for customers, who may be
unnecessarily discouraged from calling during unfavorable rate
periods, which may last for hours.
[0016] Thus, there is a need in the telecommunications industry for
systems and methods for providing telephone service that is less
cost-prohibitive than typical cellular service, and that does not
require the infrastructure of POTS.
SUMMARY OF THE INVENTION
[0017] Certain aspects and features of the various embodiments of
the present invention address the problems described above with a
cellular apparatus and service that is significantly less expensive
to provide, easier to activate, and less expensive to operate.
Reductions in cost are achieved by streamlining the cellular device
itself, automating the process of activating and servicing the
cellular device, and by providing more accurate and flexible rate
plans and signals that enable the customer and the service provider
to control the cost of service. These measures reduce the cost of
providing cellular service and serve the market demand for lower
priced cellular service.
[0018] More specifically, one aspect of the present invention is a
telephone that includes all of the features necessary to place
telephone calls, without certain features that are costly to
provide. For instance, in one embodiment, the telephone is a
stationary cellular device (SCD). The SCD lacks the unlimited
handoff capability that allows ongoing cellular telephone
conversations to be passed from any one cell site to any other cell
site. Instead, the SCD can only handoff between cell sites in a
predefined list of permissible cells. A list of permissible cell
sites for a particular SCD is stored locally in a memory in the
SCD. Whenever a call is attempted from the SCD, an originating cell
identifier and a SCD identifier are cross-referenced in a network
database that contains a remote version of the list of permissible
cells for that SCD. Alternatively, the originating cell identifier
can be compared to the list of cell IDs stored in the memory of the
SCD. If the originating cell identifier is in the list of
permissible cells for that SCD, the network permits the SCD to
place the call. Once a call is connected, the local list of
permissible cells determines whether the SCD can handoff to another
cell site. The limited handoff feature enables the service provider
to control use of system resources, while enabling the user to
handoff as needed to place and receive calls in a fixed and
predetermined area.
[0019] Another aspect of the various embodiments of the invention
is a process for activating cellular service. Using an over-the-air
activation procedure, a cellular telephone or SCD powers on and
places a call to a Customer Activation Center (CAC). The SCD
communicates identifying information regarding the SCD and the
customer to the CAC, which the CAC uses to authenticate the SCD.
The identifying information may include a terminal or device
identifier, and user information, such as a social security number
or customer ID. The identifying information can be used to validate
the provision of service to the user by checking the user's credit,
or confirming that the user has subscribed for service.
Authentication also involves associating a telephone number with
the SCD.
[0020] In a process called "orientation," the geographic location
of the SCD is determined from data that is provided by the user or
from data provided by a geopositioning system, such as a GPS or
triangulation system. The CAC "provisions" the SCD by retrieving a
list of cell IDs that correspond to that geographic location,
thereby identifying cell sites that the SCD has permission to
access. The originating cell ID for each subsequent call placed by
the SCD is compared to this list of permissible cell IDs, and
service is permitted or denied accordingly.
[0021] Yet another aspect of various embodiments of the invention
includes flexible rate plans and real-time rate signals that
benefit the CSP and the customer by providing real-time traffic
control. As used herein, the term "traffic" means the amount of
activity during a given period of time over a given communications
network element, such as a circuit, cell site, trunk, line or group
of lines, or communications switch. The CSP can optimize its
network by engineering the cellular network specifically for
reduced cost cellular service, rather than overcompensating for
statistical peaks in call traffic. Whenever call traffic actually
drives network capacity outside of an acceptable range, a CSP can
control call traffic by transmitting favorable or prohibitive cost
signals, or by delaying or disrupting service to appropriate
subscribers. In this manner, aspects of the invention facilitate
peak-shifting of customer usage according to actual fluctuations in
call traffic.
[0022] One aspect of various embodiments of traffic control is
monitoring by a Network Control Center (NCC), which can be a mobile
switching center (MSC). The Network Control Center monitors traffic
at any or all of a plurality of network elements, such as other
MSCs, cell sites, or central switching offices. The monitoring data
accumulated by the NCC is used to determine whether call traffic
control measures should be implemented.
[0023] According to this aspect, when the NCC detects that the
level of communications traffic at a particular element creates a
shortage of capacity, the NCC implements appropriate traffic
control measures. For example, if a particular cell site becomes
overloaded, calls placed by customers associated with that cell
site (and of lower priority) are restricted either actively or
passively. To do so, the customers associated with that cell site
are identified. If those customers are SCD users, a database query
can determine whether the affected cell site is one of the
permissible cell sites for those customers. Other users in the
affected area can be identified based on the relationship between
the proximity of the affected cell site and the users' location,
which can be determined for example by querying a Home Location
Register, or by GPS, triangulation or other locating means.
[0024] In certain embodiments, the traffic control aspect of the
invention is implemented by notifying the customer at the instant a
low call traffic period is detected by the CSP. The notification
includes an indication that lower rates are available during the
low call traffic period. The indication can be provided by a
visual, audible, or tactile alert means, such as but not limited to
a tone emanating from the handset, a text message or icon on a
telephone display, an incoming call to the customer, vibration
emanating from the handset, voicemail, or an audible broadcast
message. The notification may specify a fixed interval during which
lower rates are available, or a second notification may cancel the
reduced rate period. The customer may take advantage of the offer
of lower rates by responding to the notification or by simply
placing a call after receiving notification. This aspect of the
invention can also be implemented with control plans that provide
flexible levels of service--that is, levels of service that vary
according to the rates paid by the customer. Flexible service
levels can be implemented dynamically, or at initiation of the
customer-CSP relationship. For example, the customer may subscribe
at a control plan that offers a lower level of service at lower
rates than regular control plans. The lower level of service is
manifested when, during periods at which call traffic is critically
high, the customer's ability to place a call is strictly controlled
by the CSP. The customer's call may be blocked altogether, or the
call may be delayed until network capacity rises above a
predetermined level. The customer's ability to continue an ongoing
call may also be controlled, such as by the CSP disrupting a call
in progress due to critical call traffic conditions. Although these
aspects of the present invention are described in relation to
cellular service, the aspects are also applicable to landline
applications, such as long distance telephone service, or other
wireless applications, such as wireless email, internet, and text
paging.
[0025] These and other objects, features, and/or advantages accrue
from various aspects of embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings, which are incorporated in and
form a part of the specification, illustrate certain embodiments of
the present invention and, together with the description, disclose
various features and aspects of the invention. In the drawings:
[0027] FIG. 1 is a schematic of the stationary cellular device
(SCD) according to various embodiments of the invention;
[0028] FIG. 2 is a block diagram of an exemplary activation
environment of an embodiment of the invention;
[0029] FIG. 3 is a block diagram of an exemplary call traffic
control environment according to an embodiment of the
invention;
[0030] FIG. 4 is a flowchart of the operation of the stationary
cellular device, according to an embodiment of the invention.
[0031] FIG. 5 is a graphical illustration of a control scheme
according to an embodiment of the invention;
[0032] FIG. 6 is a graphical illustration of another control scheme
according to an embodiment of the invention; and
[0033] FIG. 7 is a graphical illustration of yet another control
scheme according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The Stationary Cellular Device (SCD)
[0035] FIG. 1 is a schematic of an exemplary stationary cellular
device (SCD) 100. The SCD 100 includes many of the components
common to a typical cellular or cordless telephone. The SCD 100
typically includes a handset (not separately shown), including an
earpiece and a mouthpiece. Separate from or integrated with the
handset, the SCD 100 includes a base 102. The base 102 houses a
transmitter 104, a cellular receiver 106, a baseband processor 108,
memory 110, an acoustic transducer 112, a speaker 114, an AC/DC
power converter 116, an antenna 118, and optionally, a rechargeable
or replaceable battery 120. A keypad 122 is integrated with to the
base 102, handset, or both. The keypad 122 includes buttons 124
common to telephone keypads, and may optionally include a screen.
In "corded" embodiments, the handset of the SCD 100 may be
physically connected to the base 102 via a standard telephone
handset cord. Alternatively, the SCD 100 may be "cordless" in that
the handset communicates with the base 102 wirelessly.
[0036] In a first cordless embodiment of the SCD, the base includes
two antennae. A first antenna transmits and receives cellular
signals to and from one or more cell sites. The term "cell site"
refers to a low-powered radio transmitter/receiver that serves one
geographic unit of the cellular system. A second antenna transmits
and receives radio waves to and from a cordless handset. In a
second cordless embodiment, a single base antenna transmits and
receives cellular signals to and from cell sites, as well as radio
waves to and from the cordless handset. In a third cordless
embodiment, the handset and base communicate with one another with
extremely low power calls over predetermined cellular channels. In
this third cordless embodiment, the CSP reserves a portion of a
block of proprietary cellular frequencies for extremely short range
communications. Communicating with the base over these reserved
frequency channels reduces the potential for interference from
nearby conventional cordless or cellular devices.
[0037] The SCD is preferably capable of performing a very limited
handoff function between selected cell sites that serve the home or
fixed environment so that the SCD operates well inside a home or
other fixed environment. Without some handoff ability, the cellular
receiver could not compensate for fading that occurs when a
customer moves from one area to another within the environment, or
when the environment itself changes. The cellular device must
handoff, for example, when the cellular device leaves the service
range of one permissible cell site and enters the service range of
another permissible cell site. One cell site may be appropriate for
calls made from the front of a home, while another cell site may be
appropriate for calls made from the rear of a home. Handoff
capability is also required to compensate for fluctuations in cell
site capacity and power, and for the reflectivity of radio waves.
The limited handoff function does not support unlimited handoff or
roaming, however. Limiting handoff or roaming capability can reduce
the cost of the device, and enables the SCP to control the
utilization of the network.
[0038] To limit the handoff function of the SOD, a stationary
cellular application within the baseband processor 108 of the SCD
compares the cell identifier (cell ID) of one or more accessible
cell sites with a list of one or more permissible cell IDs that is
preferably stored in the memory 110 of the SOD 100. Thus, the list
of permissible cell IDs serves at least two major purposes: the
list of permissible cell IDs 1) limits the geographic area from
which the customer is permitted to place calls using that
particular SOD, and 2) identifies the cell sites within that
geographic area between which the SOD may handoff during an ongoing
call. The SCD receives a list of permissible cell IDs during the
"activation" process, which is described below in more detail. The
list of permissible cell IDs is maintained in a network element of
the cellular system, but is also preferably stored in the memory
element of the SOD. Substantially less memory is required to
support the stationary cellular application than is required to
support typical cellular phone features, such as caller ID, memory
dialing and text paging. Thus, a smaller memory element can be
installed in the SOD so the cost of the SOD is less than a typical
cellular device. The fixed cellular application maintains the list
of permissible cell IDs, and restricts the SOD from handing-off to
cell IDs that do not appear in the list of permissible cell IDs for
that SCD.
[0039] Alternatively, the list of permissible cell IDs can be
maintained entirely at the network level. In other words, rather
than storing the list of permissible cell IDs in the SOD and
controlling handoff using the fixed cellular application, a network
level application can control handoff during an ongoing call.
[0040] The SCD application preferably searches for and utilizes the
permissible cell site that has the strongest signal, as is common
in conventional cellular communications standards, but may also
search for the closest available permissible cell site. In some
geographic areas, the CSP provides "macro cells" and "micro cells."
Most often, a macro cell provides service for the bulk of the
cellular customers in its service area. If the macro cell is
overloaded, then one or more micro cells provides "overflow"
capacity to the macro cell by carrying some of the macro cell's
calls. At least a limited handoff capability is needed for the SCD
to switch from a macro cell to a micro cell.
[0041] Activation
[0042] As mentioned above, the SCD must be activated before the SCD
is used for the first time.
[0043] In certain embodiments of the invention, over-the-air
activation procedures are used to activate the SCD. An example of
such a procedure is described in U.S. Pat. No. 5,887,253, which is
incorporated by reference. The process of activation involves the
process of authentication, which includes the SCD-specific steps of
orientation, and provisioning. The steps do not necessarily have to
be executed in a particular order. The activation process
preferably also involves several elements of a cellular network.
Each element may be a component of one or more physical network
devices.
[0044] FIG. 2 is a block diagram of an exemplary activation
environment of an embodiment of the invention. The activation
environment preferably includes a CAC 202 and one or more cell
sites 204, an MSC 206 or other switching center, and an HLR 208.
The CAC 202 may be integrated with the MSC 206, which also contains
and/or communicates with an Application Platform 210, an I.T.
System 212, an I.T. Database 213, an Application Database 214, and
an Engineering Map Database 216.
[0045] The activation process begins when the SCD 100 is powered
on. Until the SCD 100 is activated, any call attempted is
preferably automatically routed to an activation center, such as
the CAC 202. The SCD user communicates with the CAC 202 via the
most appropriate cell site 204, preferably by placing a telephone
call to a dedicated SCD activation telephone number. The SCD
activation telephone number is preferably preprogrammed into the
SCD 100, or included in the instructions for the SCD 100.
[0046] According to an embodiment of the invention, the SCD 100 is
"pre-activated," in that identifying information, including a
subscriber identifier (ID), is pre-assigned and stored within the
SCD 100 prior to purchase by the customer. North American cellular
protocol systems, such as the analog AMPS, IS-95 CDMA, and IS-136
TDMA systems, use a telephone number as the subscriber identifier.
GSM (Global System for Mobile Communications) countries assign an
International Mobile Subscriber Identifier (IMSI), which is
distinct from the phone number.
[0047] Once the communications session has been initiated, the SCD
100 transmits the identifying information to the CAC 202. The
identifying information preferably also includes a terminal
(device) identifier (such as an Electronic Serial Number (ESN), or
International Mobile Equipment Identifier (IMEI). The terminal ID
and subscriber ID are transmitted to a switching center 206, such
as a switch or a mobile switching center (MSC). The switching
center 206 provides services and coordination between customers in
the network and external networks. The switching center 206 shown
in FIG. 2 is a mobile switching center (MSC).
[0048] The majority of the steps for authenticating service for the
SCD 100 occur according to an authentication protocol for mobile
and telecommunications networks. If the subscriber ID is not used
as the telephone number, the MSC 206 uses the subscriber ID to
procure a mobile station integrated services digital network number
(MSISDN). The MSISDN is procured from a home location register
(HLR) 208. Authentication may include verification of customer
identity and credit worthiness, exchange of payment information,
and validation of the integrity of the device.
[0049] The authentication procedure for an SCD 100 includes an
additional sequence, in which the MSC 206 triggers invocation of an
Authentication Application. The Authentication Application
supplants unnecessary processes in standard authentication
protocols with the SCD-specific authentication processes
(orientation and provisioning) controlled by an Application
Platform 210.
[0050] In the HLR 208, a record exists for every service available
to the SCD 100, including call features. In the environment shown,
the HLR 208 is populated by the IT System 212, which retrieves data
from an IT Database 213. The HLR 208 also recognizes a set of
conditions as triggers such as terminating triggers, originating
call triggers, and authentication triggers. A trigger is invoked in
response a request to add, change, delete, or retrieve an
associated data element. Each trigger corresponds to an application
resident on the Application Platform 210.
[0051] In certain embodiments, the HLR recognizes receipt of
identifying information as an authentication trigger. The
authentication trigger causes the HLR 208 to instruct the MSC 206
to send the subscriber ID, terminal ID, and MSISDN (if applicable)
to the Application Platform 210. The Application Platform 210 runs
the Authentication Application (not shown), which performs
orientation and provisioning functions. The Application Platform
210 queries an Application Database 214 that contains at least a
subset of all existing cell IDs. The Authentication Application
selects from the Application Database 214 a list of permissible
cell IDs for that SCD 100, based on the geographic location of the
SCD (as determined in the orientation process). In the provisioning
process, the list of permissible cell IDs is communicated back to
the SCD 100. Each time the customer subsequently originates a call
using that SCD 100, the HLR 208 again instructs the MSC 206 to send
the identifying information to the Application Platform 210. The
originating trigger invokes an "originating call" application that
determines whether the originating cell ID (i.e., the cell ID
associated with the geographic origin of the call) is in the list
of permissible cell IDs for that SCD 100. If the originating cell
ID is in the list of permissible cell IDs, the Application Platform
informs the MSC 206, which then provides service authorization so
that the customer may complete the call. If the originating cell ID
is not in the list of permissible cell IDs, then the MSC 206 is
directed to deny service, and the Authentication Application
determines whether the SCD 100 has permission to be
re-activated.
[0052] Provisioning (i.e., limiting authorization of an originated
call to a predetermined list of permissible cell IDs) prevents the
SCD 100 from being used outside of a designated area, defined by a
location ID. The Application Platform 210 determines which of all
existing cell IDs are permissible by comparing the geographic
location of the SCD 100 at the time the customer initiates the
activation sequence with a set of associated cell IDs. The
geographic location is located in the functional equivalent of a
look-up table containing cell IDs and the geographic areas served
by the cell sites associated with the cell IDs. The list of
permissible cell IDs is preferably transmitted to the SCD 100 via a
programmable short message, or "SMS" (Short Message Service).
[0053] In the orientation process, the geographic location is
determined, preferably using a global positioning system (GPS). For
instance, CSPs typically maintain an engineering radio frequency
map database (ERFMD) 216. An ERFMD 216 is part of a software
application that predicts and empirically assesses cellular signal
strength by analyzing the power output and frequency channels of
cell sites in view of the terrain of the surrounding area. Cell IDs
for those cell sites that are capable of serving the associated
geographic area are then mapped to postal addresses, latitudes, and
longitudes. The ERFMD 216 assists system engineers in optimizing
placement of cell sites, and to "tune" the network to control the
quality of cellular service.
[0054] Alternatively, the geographic location can be determined
using triangulation based upon the signal received from the SCD.
Three or more cell sites in the vicinity of the SCD
[0055] According to certain embodiments of the invention, the
functional equivalent of an ERFMD 216 is utilized to identify the
cell IDs that should be included in the list of permissible cell
IDs for a given SCD 100. The functional equivalent of a relatively
inexpensive GPS receiver is integrated into the SCD 100. The GPS
receiver determines the location ID by calculating the precise
position of the SCD 100. A corresponding list of cell IDs is
retrieved from the ERFMD 216. The SCD 100 preferably communicates
its position to the MSC 206, which transmits the position to the
ERFMD 216 during the over-the-air activation procedure, although
other modes of communication can be employed.
[0056] System design rules control assignment of cell IDs to a
given SCD 100. For instances, an SCD 100 can be associated with a
certain number of cell IDs, cell IDs within a geographic radius, or
cell IDs with a minimum amount of available capacity.
[0057] In an alternative embodiment, the geographic location is
determined based upon customer input at the time of activation. For
instance, the activation sequence may prompt the customer to
indicate his or her location using interactive voice response (IVR)
and/or touchtone inputs. The customer's inputs are translated into
a location ID. The customer's billing and other demographic data
can also be obtained during activation, using the same input
methods.
[0058] In yet another embodiment, the geographic location is
determined based on the RF (radio frequency) signal received from
the SCD by surrounding cell sites. Each of the surrounding cell
sites detects the strength of the signal emitted by the SCD, and
the original transmit power level from the SCD. The signal strength
and transmit power level are used to determine the bit error rate
of the signal. Each of the surrounding cell sites sends the bit
error rate information associated with the SCD to the Application
Platform, which determines the location of the SCD using a location
algorithm.
[0059] After initial activation of the SCD 100, the ability of a
customer to change the location ID, and thus, the permissible list
of cell IDs is controlled using a flexible rule set. The flexible
rule set prohibits changes, for example, during a given timeframe
or of a given degree, or imposes a financial disincentive upon the
customer. This control is necessary to prevent the customer from
circum-venting the limited handoff function of the SCD 100 by
repeating the activation procedure each time the customer changes
geographic locations. The flexibility of the rule set permits the
customer to rectify inadvertent errors committed during the
activation procedure.
[0060] The authentication process occurs each time the SCD is
powered on. The orientation process should only occur if no list of
permissible cell IDs has been established, if the originating cell
ID is not in the list of permissible cell IDs, and if permission is
granted through the authentication process to "re-orient." The
provisioning process should only occur in limited circumstances,
such as the first time the SCD is powered on, when permissible cell
IDs are added or removed at the network level, or when the customer
moves or transfers ownership of the SCD. Re-orientation can be
permitted when the SCD "permanently" moves from one geographic
location to another. For example, the customer may be required to
periodically "re-provision" the SCD, so that the list of
permissible cell IDs stored in the memory of the SCD is updated
with any new cell IDs that have been associated with the customer's
location ID. The flexible rule set discourages re-provisioning if
the change in geographic location is temporary.
[0061] Operation
[0062] FIG. 4 is a flowchart of the operation of the stationary
cellular device 100, according to an embodiment of the invention.
At 400, the SCD is powered on. At 402, identifying information is
sent from the SCD to the MSC. At 404, either the MSC or the SCD
determines whether the SCD has been activated. This determination
can be made by any number of appropriate mechanisms, such as
checking for an initialization flag stored in the memory of the SCD
or in the Application Database, or by determining whether a set of
permissible cell IDs has previously been downloaded to the SCD. If
the SCD has not been activated, the orientation and provisioning
processes of authentication, described herein, are performed at 406
and 408. If the SCD has been previously activated, at 410, the
originating cell ID of the attempted call is checked against the
set of permissible cell IDs for that SCD at least in part to ensure
that the customer is calling from an originating cell ID that
corresponds to a cell ID in the customer's list of permissible cell
IDs.
[0063] In certain embodiments of the invention, this "originating
call ID check" occurs within the SCD. In these embodiments, the SCD
receives the originating cell ID from the originating cell site or
from the MSC. An application stored within the SCD then compares
the originating ID to the list of permissible cell IDs stored
within the SCD. If the originating cell ID is in the list of
permissible cell IDs, the SCD sends an authentication indicator
(such as a flag) to the MSC. The authentication indicator indicates
that the call is allowable, and enables the MSC, at 412, to route
the call to its intended recipient. If the originating ID is not in
the list of permissible cell IDs, then in these embodiments,
operation proceeds from 410 to 416 and the SCD terminates the
attempted call (414 is not applicable).
[0064] In other embodiments, the originating call ID check occurs
at the network level. Upon attempting a call, the SCD communicates
identifying information to the MSC, which causes the Application
Platform to compare the originating cell ID to the list of
permissible cell IDs, which can be obtained from the Application
Database based on the terminal ID of the SCD. If the originating
cell ID is not in the list of permissible cell IDs, then at 414,
the Authentication Application determines whether re-activation is
permissible, according to flexible rules imposed by the CSP. The
flexible rules may allow re-activation at set intervals, upon
payment of a fee, or when the customer has made arrangements with
the CSP to re-activate the SCD. If re-activation is not
permissible, then at 416, the MSC terminates the attempted
call.
[0065] Once a call is connected, the SCD application uses the list
of permissible cell IDs stored within the SCD to determine
permissible handoff cell sites.
[0066] Call Traffic Control
[0067] To further reduce customer and provider costs associated
with cellular service, systems and methods for providing real-time
call traffic control are provided. According to certain embodiments
of the invention, upon attempting to place a call, customer
identification information is communicated to the MSC 206. The
subscriber ID or other identifying information preferably indicates
the control plan to which the customer subscribes. The customer's
control plan dictates the control measures that the customer has
typically agreed to accept in exchange for lower rates. Referring
to FIG. 3, each cellular network has a Network Control Center (NCC)
300, which can be an MSC 206 (or the functional equivalent).
Occupancy data is relayed to the NCC 300. The occupancy data
indicates the traffic offered and carried at various levels of
communications network elements or sub-elements. In a cellular
network, these network elements are "cellular facilities," which
can include individual or groups of cell sites, MSCs, or RF
channels. In a landline system, the network elements include POTS
facilities such as central offices and trunks. For example, the
occupancy data at each MSC 206, cell site 204, and RF channel in
each cell site on the cellular network can be communicated to the
NCC 300. An algorithm at the NCC 300 translates the occupancy data
into traffic intensity, which is typically a measure of the average
occupancy of the particular network element which is to carry the
call. Traffic intensity is preferably expressed using an Erlang
formula, such as the Erlang B probability of blocking P.sub.b: P b
= E N / N ! k = 0 N .times. E k / K ! ##EQU1## where: [0068] E
(traffic intensity)=.lamda. t.sub.h Erlangs, [0069] .lamda.=call
arrival rate (calls/hour), [0070] t.sub.h=mean holding time
(hours/call), and [0071] N=total number of channels. A traffic
intensity of one Erlang means the cell site has been continuously
occupied during the time period under consideration. Traffic
intensity can be calculated using any effective mathematical
expression, such as Erlang C, centum call seconds (CCS), or
capacity factor.
[0072] The NCC 300 passes the traffic intensity data to a Traffic
Engineering Application 302, which processes the traffic intensity
data to monitor the traffic on the cellular network. The Traffic
Engineering Application 302 populates a Traffic Engineering
Database 304 with data that quantifies the traffic level seen by
the NCC 300. One appropriate metric is the probability of blocking
P.sub.b for each cell site, by cell ID, and by MSC 206. Traffic
intensity data from multiple NCCs 300 can be processed and stored
in the Traffic Engineering Database 304.
[0073] The CSP launches a Traffic Control Application from the
Application Platform 210. The Traffic Control Application extracts
data from the Traffic Engineering Database 304, preferably in real
time. Based on the traffic intensity (also known as the Grade of
Service), the Traffic Control Application then applies a set of
rules to determine whether traffic control measures should be
implemented in a particular geographic area.
[0074] According to various aspects of certain embodiments of the
invention, if the probability of blocking P.sub.b indicates a
shortage of capacity on a cell or group of cells, then the Traffic
Control Application queries the HLR 208 and retrieves a list of
affected cellular devices that are in the affected area and
associated with subscriber IDs that are to be controlled. The
Traffic Control Application instructs the affected MSC 206 and the
HLR 208 to implement the appropriate passive or active control
scheme until the traffic intensity condition improves. In addition,
the Traffic Control Application notifies the IT System 212 of the
commencement of a control period for those particular customers.
This notification is communicated to a billing application so the
prices charged to the customers correspond to the control scheme
that is implemented.
[0075] According to various embodiments of control schemes of the
present invention, each customer subscribes to a control plan
associated with a grade of service (GOS). As an example, customers
subscribing at the most permissive grade of service (GOS0) may
never be controlled, that is, purposefully discouraged or prevented
from placing calls. However, all other grades of service are
subject to varying degrees of control as the network becomes more
congested. Typically, the grades of service that are subject to
more control are more affordable. FIG. 5 shows the relationship
between affected customers and network congestion, according to one
such control scheme. In one embodiment, a first control point C1 is
reached when the probability of blocking P.sub.b exceeds a certain
value, such as 0.5, which indicates that the cell site is 50%
occupied. A second control point C2 is reached when the probability
of blocking P.sub.b exceeds higher value, such as 0.65, which
indicates that the cell site is 65% occupied. An nth control point
Cn is reached when the probability of blocking P.sub.b exceeds a
predefined absolute maximum n. Both the probability of blocking
that defines each control point and the number of control points
are variable according to the CSP's requirements at the time
control is implemented. The values of P.sub.b in the examples are
given to illustrate the use of multiple control points, and not to
establish preferences as to particular control schemes or number of
control points.
[0076] At control point C1, the CSP either passively or actively
controls the traffic of calls placed by customers subscribing to a
control plan that corresponds to that grade of service. These
customers will be referred to as "GOS1" customers, because at
control point C1, customers subscribing to control plans that fall
within grade of service 1 will be controlled for the first time. At
control point C2, the CSP either passively or actively controls the
traffic of calls of GOS2 customers. In addition, at control point
C2, the CSP continues to control GOS1 customers, and may increase
the severity of the control, such as by switching from passive to
active control. At control point Pn, the CSP may elect to actively
control the traffic of calls placed by all customers subscribing to
any reduced cost control plan.
[0077] Control points can be established and implemented system
wide, or can vary by cell site, geographic area, season, time of
day, or other parameter. In other words, the CSP can determine that
a 5% probability of blocking P.sub.b is acceptable on weekends, but
not on weekdays.
[0078] Certain embodiments of the invention implement active
control of call traffic by limiting or denying some customers'
access of the network during periods of increased call traffic. In
an example of an active control scheme according to these
embodiments, if the probability of blocking P.sub.b at a given cell
site has reached control point C1, then the number and/or duration
of calls placed by GOS1 customers in that area can be limited to
predetermined maximum values. If the congestion on the network
causes the probability of blocking P.sub.b to reach control point
C2, GOS1 customers are denied service altogether, and GOS2
customers are prevented from exceeding maximums for number and/or
duration of calls placed during the period of control. As an
alternative to denying service, the CSP may delay the connection of
calls placed by certain customers to prevent those customers from
having to attempt the calls repeatedly. Rather, the CSP can
generate an audible message that informs the customer that a call
will be connected at a later time. Preferably, the customer may
accept the delay, or cancel the attempt.
[0079] In an active control scheme, the CSP can elect to interrupt
service to or limit the duration of calls that were underway prior
to the commencement of a call traffic control period. To mitigate
the impact on customer service, the CSP can notify the customer of
an imminent service disruption using any of the notification
methods described hereinafter. After notification is given, the
customer has sufficient time to conclude the ongoing telephone call
before the call is disconnected.
[0080] Other embodiments of the invention implement passive control
of call traffic by dynamically establishing rates according to the
grade of service that corresponds to the customer's control plan.
For instance, if at time t, the Traffic Control Application
determines that the probability of blocking P.sub.b at a given cell
site has reached control point C1, GOS1 customers in that area must
pay an increased rate to place a call. The degree of this dynamic
rate increase is calculated to achieve the desired effect of
discouraging a given percentage of affected GOS1 customers from
placing calls during the period that the increased rate is
applicable. To reduce call traffic, the affected customers are
notified at the same time as the rate increase is dynamically
imposed. After the probability of call blocking P.sub.b falls below
control point C1, signaling that the decrease in call traffic has
in fact occurred, the rate increase is reversed. GOS1 customers are
similarly informed that the period of increased rates has ended or
will end at a given time, or when the desired effect has been
obtained.
[0081] FIG. 6 is a diagram of a passive control scheme, where
increasing premiums are added to the rates of particular tiers of
customers as capacity conditions erode. In the example shown, an
initial 10% premium is imposed on GOS1 customers when the
probability of blocking P.sub.b reaches control point C1. GOS2
customers are unaffected at control point C1. At control point C2,
GOS1 customers incur an additional 10% premium (for a total of
20%), while an initial 10% premium is imposed on GOS2 customers.
Both GOS1 customers and GOS2 customers are notified of the
applicable rate increases that apply at control point C2.
Preferably, when the system capacity has reached a critical
shortage condition at control point Pn, the applicable premiums are
sufficient to effectively preclude call traffic attributable to
customers at the lowest grades of service.
[0082] Conversely, passive control can be implemented to encourage
increases in call traffic during periods of excess capacity. In
this instance, increased call traffic is desirable to generate
additional revenue, to optimize network utilization, and to allow
customers opportunities to place more affordable discretionary
calls. To increase call traffic, the customer is notified that rate
discounts will be implemented for a period of time. At the end of
the discount period, the customer will be notified that the
discount no longer applies. Referring to FIG. 7, if the probability
of blocking P.sub.b at one or more given cell sites falls below a
given discount point D1, some or all of the customers in the
affected area are offered a discounted rate for calls. A discount
point defines the traffic intensity level at which the CSP offers a
discount. The discount is applicable for a fixed period of time, or
expires when the probability of blocking P.sub.b rises above D1.
The discount may be implemented as a percentage reduction in rates,
or as a pre-determined flat rate (e.g., 5 cents per minute). As the
capacity surplus increases, the discount increases. For instance,
at D1, customers may receive a 50% rate reduction. If the
probability of blocking P.sub.b falls further to D2, customers may
receive a 75% rate reduction. In any case, the degree of the
dynamic rate discount is calculated to achieve the desired effect
of encouraging customers to place more calls during the period that
the discount is applicable.
[0083] Various aspects of the embodiments of traffic control
schemes can be implemented in non-cellular applications, especially
with respect to long distance service. For non-cellular systems,
the NCC determines traffic parameters by monitoring loads on
various network switches, network trunks between switches,
distribution trunks from switches to end customers, network
distribution points, and at network control points. Customers can
be notified of load-based variations in pricing using one-way or
two-way pagers, distinctive stutter dial tones, distinctive
ringing, voicemail, outbound calls from an IVR, email, instant
messaging, or any combination of these notification mechanisms.
[0084] Notification of the Commencement or Conclusion of Traffic
Control Customer notification of the increased or reduced calling
rates is pre-ferably performed by sending a commencement message
when the adjustment period begins, followed by a concluding message
when the adjustment period ends. Notification can be accomplished
with an SMS message to the customer's handset. If the handset has
no display, the customer can receive notification via a tone or
beep, similar to the audible alert commonly used to indicate that a
cellular customer has a voice message. If the handset has a
display, notification can be received as a text message along with
or in lieu of the audible tone. The text message includes a short
description of the rate adjustment, such as "10% off all calls now"
or "reduced rate ends in 2 minutes." An icon or other graphic can
communicate the same information. For example, "$" can indicate a
10% rate increase, "$$$" can indicate a 30% rate increase, and
"-$$" can indicate a 20% rate reduction. Similarly, audible tones
with different pitches can differentiate between an increase as
opposed to a discount; the number of tones can indicate the amount
of the adjustment. Alternatively, a particular melody or a
prerecorded message can designate commencement or conclusion of a
period of rate adjustment.
[0085] Rather than using an SMS message for notification of
commencement or conclusion of a period of rate adjustment, a call
can be placed to each affected customer. When the customer answers
the call, notification is provided via a prerecorded message. This
alternative is less attractive for providing notification of
temporary rate increases due to capacity shortages, because the
notification calls would further increase the already elevated call
traffic on the affected portion of the network.
[0086] The foregoing description of a preferred embodiments of the
invention has been presented only for the purpose of illustration
and description and is not intended to be exhaustive or to limit
the invention to the precise forms disclosed. Many modifications
and variations are possible in light of the above teaching. For
example, the notification and control aspects of the invention are
directed to cellular service, but can be implemented in any
subscriber media, such as POTS, text paging, wireless internet,
long-distance, cable, satellite, and internet services. The term
"call" includes any communications session initiated or received in
any such subscriber medium. In addition, passive or active control
of call traffic can be implemented proactively or reactively. For
example, a control scheme can be implemented reactively by
calculating the probability of blocking P.sub.b on a given cell
site only in response to an attempted call, and then by imposing
rate adjustments or denying service to that particular customer if
warranted by the capacity situation at that particular time.
[0087] Various modifications are possible, including additions,
changes, deletions as are suited to the particular use
contemplated, without departing from the principles and scope of
the invention.
* * * * *