Adding groups to sharepoint site using powershell

Question

Hi I have added 4 groups to site collection 'A' using the powershell script below. How can I add the same groups in a site under the site collection 'A'

   `$web=Get-SPWeb "http://sitecollectionurl"`
    $newGroup=$web.SiteGroups.Add($groupName,$web.Site.Owner,$web.Site.Owner,$description) 
    $group=$web.SiteGroups[$groupName] 
    $roleAssignment=New-Object Microsoft.SharePoint.SPRoleAssignment($group) 
    $roleDefinition=$web.RoleDefinitions[$permissionLevel] 
    $roleAssignment.RoleDefinitionBindings.Add($roleDefinition) 
    $web.RoleAssignments.Add($roleAssignment); 
    $web.Update() 
    $web.Dispose() 

Answer 1

Groups are created at the site collection level only.

It is only what permissions that group has in the sub site that is maintained (in a sub site with broken inheritance) in the sub site

See this for more information: http://social.msdn.microsoft.com/Forums/sharepoint/en-US/e6981b2b-924b-4b0c-bcb8-4f9748119170/add-new-group-to-subsites-programatically?forum=sharepointdevelopmentlegacy