EXHIBIT 10.31

                                ADDENDUM II
                                     TO
                      SPRINT PCS MANAGEMENT AGREEMENT



MANAGER:    ALAMOSA PCS LLC

SERVICE AREA BTAS:

Flagstaff, AZ # 144                            Abilene, TX # 3
Phoenix, AZ # 347 (Navajo County, AZ)          Amarillo, TX # 13
Prescott, AZ # 362                             Eagle Pass, TX # 121
Grand Junction, CO # 168                       El Paso, TX # 128
Pueblo, CO # 366                               Laredo, TX # 242
Albuquerque, NM # 8                            Lubbock, TX # 264
Carlsbad, NM # 68                              Midland, TX # 296
Farmington, NM-Durango, CO # 139               Odessa, TX # 327
Gallup, NM # 162                               San Angelo, TX # 400
Las Cruces, NM # 244
Roswell, NM # 386
Santa Fe, NM # 407

EXPANSION SERVICE AREA BTAS:

Las Vegas, AZ # 245 (portion of Mohave County)
Colorado Springs, CO # 89 (portion of El Paso County)
Phoenix, AZ # 347 (portion of Maricopa and Pinal County)
Clovis, NM # 87
Sierra Vista-Douglas, AZ # 420
Hobbs, NM # 191
Tucson, AZ # 447 (portion of Pima County)
Big Spring, TX # 40
Yuma, AZ # 486
El Centro-Calexico, CA # 124
San Diego, CA # 402 (portion of San Diego County)


            This Addendum II (this "ADDENDUM"), dated as of February 3,
2000, and effective as of February 8, 2000, contains certain additional and
supplemental terms and provisions of that certain Sprint PCS Management
Agreement entered into as of December 23, 1999, by the same parties as this
Addendum, which Management Agreement was further amended by that certain
Addendum I entered into as of December 23, 1999 (the Management Agreement,
as amended by Addendum I, being the "MANAGEMENT AGREEMENT"). The terms and
provisions of this Addendum control, supersede and amend any conflicting
terms and provisions contained in the Management Agreement. Except for
express modifications made in this Addendum, the Management Agreement
continues in full force and effect.

            Capitalized terms used and not otherwise defined in this
Addendum have the meanings ascribed to them in the Management Agreement.
Section and Exhibit references are to Sections and Exhibits of the
Management Agreement unless otherwise noted.

            The Management Agreement is modified as follows:

            1. USE OF LOAN PROCEEDS. Sprint PCS is entering into that
      certain Amended and Restated Consent and Agreement with Nortel
      Networks Inc. ("NORTEL") to amend and restate the Consent and
      Agreement with Nortel, dated June 10, 1999 (which Amended and
      Restated Consent and Agreement, as amended and modified from time to
      time, is referred to as the "CONSENT AND AGREEMENT") to enable
      Manager (which, by the effective date of this Addendum II, will have
      reorganized into a holding company structure, with Texas
      Telecommunications, L.P. being the operating subsidiary and
      "Manager") to continue to obtain loans indirectly from Nortel and its
      successors and assigns (collectively, the "LENDERS") through
      Manager's limited partner, Alamosa PCS, Inc. ("ALAMOSA PCS"). Manager
      agrees that it will not use the proceeds from any loan made by Nortel
      to Alamosa PCS to which the Consent and Agreement relates or from any
      other loan or extension of credit to which the Consent and Agreement
      relates (whether such loan proceeds are received by Manager pursuant
      to a loan or a capital contribution from its partners) for any
      purpose other than (a) to construct and operate the wireless service
      within the Service Area (as may be amended from time to time) as
      contemplated under the Management Agreement, or (b) as expressly
      permitted under Section 2.10 of the Amended and Restated Credit
      Agreement between Nortel, Alamosa PCS and certain other entities
      dated as of February 8, 2000 (the "CREDIT AGREEMENT"), as in effect
      as of the date of execution thereof (a copy of which is attached to
      this Addendum as Exhibit A) without giving effect to any subsequent
      amendment, modification or waiver of any term, condition, definition
      or other provision of the Credit Agreement or to any course of
      dealing between Nortel and Alamosa PCS that now exists or may
      hereafter be established allowing a use of loan proceeds not allowed
      in Section 2.10 of the Credit Agreement as in effect as of the date
      hereof.

            2. CONSENT AND AGREEMENT NOT ASSIGNABLE. Except as expressly
      required or permitted in the Consent and Agreement, Manager may not
      assign the Consent and Agreement.

            3. NOTICES. Manager agrees to promptly give Sprint PCS a copy
      of any notice Manager receives from the Administrative Agent or any
      Lender (as those terms are defined in the Consent and Agreement), and
      a copy of any notice Manager gives to the Administrative Agent or any
      Lender. Sprint PCS agrees to promptly give Manager a copy of any
      notice Sprint PCS receives from the Administrative Agent or any
      Lender, and a copy of any notice that Sprint PCS gives to the
      Administrative Agent or any Lender.

            4. REVISED FINANCING PLAN. Exhibit 1.7 attached to this
      Addendum supersedes and replaces in its entirety Exhibit 1.7 attached
      to the Management Agreement.

            5. NO DEFAULT UNDER CREDIT AGREEMENT OR MANAGEMENT AGREEMENT.
      Manager warrants and represents that as of the date hereof, no
      Default or Event of Default under the Credit Agreement has occurred,
      and no Event of Termination under the Management Agreement or event
      that if not cured, or if notice were to be provided, would constitute
      an Event of Termination under the Management Agreement, has occurred.

            6. NO KNOWN BREACH UNDER MANAGEMENT AGREEMENT. Sprint PCS
      warrants and represents that, to the knowledge of its officers, as of
      the date hereof, no Event of Termination under the Management
      Agreement or event that if not cured, or if notice were to be
      provided, would constitute an Event of Termination under the
      Management Agreement, has occurred that has not been waived.

            7. SHARING CONFIDENTIAL INFORMATION WITH LENDERS. Section
      12.2(b)(vii) of the Management Agreement is amended by inserting the
      words "or has provided" between the words "is considering providing"
      and "financing."

            8. REAFFIRMATION OF SPRINT AGREEMENTS. Each of the undersigned
      reaffirms in their entirety, together with their respective rights
      and obligations thereunder, the Management Agreement, the Services
      Agreement and the License Agreements.

            9. COUNTERPARTS. This Addendum may be executed in two or more
      counterparts, each of which shall constitute an original but all of
      which when taken together shall constitute but one agreement.

      [The remainder of this page has been intentionally left blank.]


      IN WITNESS WHEREOF, the parties hereto have caused this Addendum II
to be executed by their respective authorized officers as of the date and
year first above written.

                                    SPRINT SPECTRUM L.P.


                                    By:  /s/ Bernard A. Bianchino
                                        -------------------------
                                          Bernard A. Bianchino
                                          Senior Vice President and
                                          Chief Business
                                          Development Officer -
                                          Sprint PCS


                                    WIRELESSCO, L.P.


                                    By: /s/ Bernard A. Bianchino
                                        ------------------------
                                          Bernard A. Bianchino
                                          Senior Vice President and
                                          Chief Business
                                          Development Officer -
                                          Sprint PCS


                                    SPRINTCOM, INC.


                                    By:  /s/ Bernard A. Bianchino
                                         ------------------------
                                          Bernard A. Bianchino
                                          Vice President


                                    COX COMMUNICATIONS PCS, L.P.


                                    By:  /s/ Bernard A. Bianchino
                                         ------------------------
                                          Bernard A. Bianchino
                                          Senior Vice President and
                                          Chief Business
                                          Development Officer -
                                          Sprint PCS


                                    COX PCS LICENSE, LLC


                                    By:  /s/ Bernard A. Bianchino
                                         ------------------------
                                          Bernard A. Bianchino
                                          Senior Vice President and
                                          Chief Business
                                          Development Officer -
                                          Sprint PCS


                                    SPRINT COMMUNICATIONS COMPANY, L.P.


                                    By:  /s/ Don A. Jensen
                                        ---------------------------
                                        Don A. Jensen
                                        Vice President - Law


                                    ALAMOSA PCS LLC


                                    By:  /s/  David Sharbutt
                                         --------------------------
                                         David Sharbutt
                                         Chairman of the Board of Managers