the present invention will be discussed as embodied on a full duplex fddi ii ring network having a 100 mbps bandwidth . the ring network has 20 attached stations , each requiring a 20 mbps channel . this is depicted graphically in fig1 . in the preferred embodiment , the ring network is comprised of a dual media access control ( mac ) fddi ii network . in ring networks such as the one described above , real - time , isochronous information ( such as moving images and voice ) is allocated on a channel basis . in the fddi ii network in question ,, the 100 mbps bandwidth can be divided into 1536 - 64 kbps channels or any combination of these channels . since each of the 20 attached stations required a 20 mbps channel , in the prior art a total of 400 mbps ( 20 stations × 20 mbps per station ) worth of bandwidth is needed for the stations to communicate with each other . since fddi ii is only 100 mbps , these 20 stations could not all operate simultaneously on the network . it should be noted , however , that in practice , each station does not have a need to communicate to each of the other 19 stations simultaneously . rather , a station will normally require communication which some subgroup of the total . this fact opens up the possibility of assigning a portion of the bandwidth to a group of stations , and then reassigning the bandwidth to another group . the method by which this is accomplished , referred to as spacial reuse , is described in more detail below . the simplest implementation of spacial reuse occurs when the groups of stations on a ring network that wish to communicate with each other form contiguous , non - overlapping subgroups . this will be referred to as linearly distributed groups . for example , in the ring network of fig1 the communications requirements of the station could essentially divide the ring into five linearly distributed communications groups : communication group 1 , comprised of stations 1 - 4 , ( 21 ); communication group 2 , comprised of stations 5 - 8 ( 22 ); communication group 3 , comprised of stations 9 - 12 ( 23 ); and communications group 4 , comprised of stations 13 - 16 ( 24 ); and communications group 5 , comprised of stations 17 - 19 ( 25 ). ( note that the stations in each group are contiguous : that is , if the first station x and last station y in a group g are considered the end points of an arc on the circle formed by the ring network , each station lying on that arc -- or between station x and station y -- belongs to group g . in contrast , in the communications group formed of the stations 1 , 2 , 4 , the stations are not contiguous and hence this group would not be linearly distributed .) were unlimited bandwidth available , if each station required 20 mbps , then each group would be assigned one of channels a through e , each having an allocated bandwidth of 80 mbps . this is shown in table 1 . using the concept of spacial reuse of the present invention , however , each of the five groups is reallocated the same channel s at 80 mbps . ( this is shown in table 2 .) because each group is full duplex and contains its communication only within its own group , the channel is free for reuse outside of the spatial group . more particularly , assume channel s is comprised of the bands from 20 to 100 mbps , and further assume that station 6 needs to send message 2 to station 7 , within communication group 2 ; station 9 needs to send message 3b to station 12 within communication group 3 ; and station 10 needs to send message 3a to station 11 in communication group 3 . station 6 will use 40 - 60 mbps , station 9 will use 20 - 40 mbps , and station 10 will use 40 - 60 mbps . thus , reuse will occur for the bandwidth assigned to station 6 and station 10 . the details of the operation are as follows . station 6 will send message 2 to station 7 , occupying the clockwise bandwidth 40 - 60 mbps as the message travels between station 6 and station 7 . station 7 receives the message . at this point , data in 40 - 60 mbps is no longer required . this bandwidth is then free for station 10 ( which is &# 34 ; further down the line &# 34 ; on the ring network in terms of data traffic proceeding counterclockwise ) to use to send its message to station 11 . in the meantime , station 9 uses 20 - 40 mbps to communicate with station 12 . the bandwidth is not required once the traffic passes station 12 , hence , station 13 can make use of it if it wishes to communicate with any of the other stations in communication group 4 . this utilization is shown in fig3 . for an originating station requiring communications with a station in its subgroup situated in a counter - clockwise direction from it ( in fig1 this is equivalent to a station in a subgroup with a lower number than the originating station ), the bandwidth moving in the counterclockwise direction is used . a somewhat more complex situation occurs when the communication groups are &# 34 ; nested .&# 34 ; generally , two types of nesting can occur : regular nesting and cross boundary nesting . regular nesting ( or just nesting ) occurs when one group of stations is spatially located entirely within another group . for example , assuming stations are sequentially numbered clockwise , the communication group a consisting of stations 4 - 5 and 6 , is nested within the communication group b consisting of stations 1 , 2 , 3 , 4 , 5 , 6 and 7 . in this situation , as graphically depicted in fig2 communication group a ( 31 ) is nested within communication group b ( 32 ). cross boundary nesting ( or cb nesting ) occurs when two groups partially overlap so that one group extends across the boundary of the other . referring to fig3 communication group c ( 41 ) consisting of stations 4 , 5 and 6 is cb - nested in the communication group d ( 42 ) consisting of stations 1 , 2 , 3 and 4 . communications groups which do not overlap with any other group are referred to as independent groups . for example , referring to fig3 communication group e ( 43 ), consisting of stations 10 , 11 , and 12 , is independent of communication groups c and d . the operation of the invention in a nesting situation is as follows . consider a configuration of five groups depicted in fig4 : group 1 ( 51 ) is independent ; group 2 ( 52 ) is nested entirely within group 3 ( 53 ); and finally group 4 ( 54 ) and group 5 ( 55 ) are cb nested . in this configuration , under spacial reuse , channel s will be allocated to groups 1 , 2 , and 4 . these groups can be allocated the same channel because they are independent of each other . groups 3 and 5 can then also be allocated their own separate channel t because they are independent of each other . they must be assigned a different channel than the other groups because they are not independent ( nesting wise ) of the other groups . also , groups 1 , 2 , and 4 all reuse the same channel because they are nest - wise independent . the same holds for groups 3 and 5 . the stations of each group and their channel allocations are shown in table 3 . in the case of a non - contiguous communications group n , it can be observed that the invention may also be used provided those stations which , if included in group n would make n contiguous , are not required to be in another communication group . in essence , they are included in communications group n to make it linearly distributed . in order to implement the spatial reuse concept on a ring network like fddi , a management agent software would have to keep a logical and physical ring map ( which is part of the fddi standards ) and would have to allocate the channels based on spatial grouping . this algorithm would have to determine the physical ring map , determine the spatial groupings , determining the nesting between the groupings , and allocate the channels based on the independent groups . ( in this context , independent refers to groups that are not nested .) it can be observed that if there are no nested groups then all groups may be assigned the same single channel . for each nesting of groups an additional channel allocation will have to be provided ( one for each nest and / or each level of nesting ). thus it can be seen that by using spatial reuse , the bandwidth of a ring network can be enormously extended . although the implementation of the invention has been disclosed within the context of a fidi ii ring network , the invention can also find application in any ring - topology network . although a specific embodiment of the invention has been disclosed , it will be understood by those having skill in the art that changes can be made in the specific embodiment disclosed , without departing from the spirit and scope of the invention . table 1______________________________________prior art additionalgroup channel bandwidth allocated ( mbps ) ______________________________________1 . 1 - 4 a 802 . 5 - 8 b 803 . 9 - 12 c 804 . 13 - 16 d 805 . 17 - 20 e 80 total allocation : 400 mbps______________________________________ table 2______________________________________ additionalgroup channel bandwidth allocated ( mbps ) ______________________________________1 . 1 - 4 s 802 . 5 - 8 s / 3 . 9 - 12 s / 4 . 13 - 16 s / 5 . 17 - 20 s / total allocation : 80 mbps______________________________________ table 3______________________________________ additionalgroup channel bandwidth allocated ( mbps ) ______________________________________1 . 1 - 4 s 802 . 6 - 8 s / 3 . 5 - 9 t 804 . 11 - 15 s / 5 . 15 - 17 t / total allocation : 160 mbps______________________________________